FN Thomson Reuters Web of Science™ VR 1.0 PT S AU Gruber, J George, DC Kuprat, AP Rohrer, GS Rollett, AD AF Gruber, J George, DC Kuprat, AP Rohrer, GS Rollett, AD BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Effect of anisotropic interfacial energy on grain boundary distributions during grain growth SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, arcelor, Rhone Alpes, ESIA DE grain growth; grain boundaries; microstructure; simulation ID MAGNESIA AB Through simulations with the moving finite element program GRAIN3D, we have studied the effect of anisotropic grain boundary energy on the distribution of boundary types in a polycrystal during normal grain growth. An energy function similar to that hypothesized for magnesia was used, and the simulated grain boundary distributions were found to agree well with measured distributions. The simulated results suggest that initially random microstructures develop nearly steady state grain boundary distributions that have local maxima and minima corresponding to local minima and maxima, respectively, of the energy function. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gruber, J (reprint author), Carnegie Mellon Univ, Dept Mat Sci & Engn, 5000 Forbes Ave, Pittsburgh, PA 15213 USA. RI Rollett, Anthony/A-4096-2012; Rohrer, Gregory/A-9420-2008; OI Rollett, Anthony/0000-0003-4445-2191; Rohrer, Gregory/0000-0002-9671-3034; Kuprat, Andrew/0000-0003-4159-918X NR 7 TC 5 Z9 5 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 733 EP 738 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800115 ER PT S AU Basanta, D Miodownik, MA Holm, EA Bentley, PJ AF Basanta, D Miodownik, MA Holm, EA Bentley, PJ BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Evolving 3D microstructures using a Genetic Algorithm SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE Materials Science Forum LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, Arcelor, Rhone Alpes, ESIA DE evolutionary computing; genetic algorithms; cellular automata; stereology; microstructures AB We describe a general approach to obtaining 3D microstructures as input to computer simulations of materials properties. We introduce a program called MicroConstructor, that takes 2D micrographs and generates 3D discrete computer microstructures which are statistically equivalent in terms of the microstructural variables of interest. The basis of the code is a genetic algorithm that evolves the 3D microstructure so that its stereological parameters match the 2D data. Since this approach is not limited by scale it can be used to generate 3D initial multiscale microstructures. This algorithm will enable microstructural modellers to use as their starting point, experimentally based microstructures without having to acquire 3D information experimentally, a very time consuming and expensive process. C1 Kings Coll London, Dept Mech Engn, London WC2R 2LS, England. Sandia Natl Labs, Albuquerque, NM 87185 USA. UCL, Dept Comp Sci, London, England. RP Basanta, D (reprint author), Kings Coll London, Dept Mech Engn, London WC2R 2LS, England. RI Holm, Elizabeth/S-2612-2016; OI Holm, Elizabeth/0000-0003-3064-5769; Bentley, Peter/0000-0001-6744-9302 NR 10 TC 2 Z9 2 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI STAFA-ZURICH PA LAUBLSRUTISTR 24, CH-8717 STAFA-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1019 EP 1024 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800159 ER PT S AU Harun, A Miodownik, MA Clode, MP Holm, EA AF Harun, A Miodownik, MA Clode, MP Holm, EA BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Modelling Zener pinning: A comparison of different computer simulation methods SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, Arcelor, Rhone Alpes, ESIA DE microstructure evolution; Zener pinning; Monte Carlo Potts model; phase field model ID GRAIN-GROWTH; FIELD MODEL AB We compare the ability of three different types of microstructural model to simulate particle pinning. The microstructural models are the Phase Field model, the Front Tracking model and the Monte Carlo Potts model. The same 3D test geometry is simulated using each method. This is an hexagonal network with spherical particles located at the centre of each hexagonal grain. The hexagonal grain network provices a constant driving force for a moving boundary and includes triple line and quadruple point motion. This geometry allows detailed investigation of the boundary/particle interaction. The pinning force acting on the migrating curved grain boundary is calculated and compared with theoretical predictions for each model. C1 Kings Coll London, Dept Mech Engn, London, England. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Harun, A (reprint author), Kings Coll London, Dept Mech Engn, London, England. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 8 TC 2 Z9 2 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1033 EP 1038 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800161 ER PT S AU Holm, EA Meinke, JH McGarrity, ES Duxbury, PM AF Holm, EA Meinke, JH McGarrity, ES Duxbury, PM BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Critical manifolds in polycrystalline grain structures SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE Materials Science Forum LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, Arcelor, Rhone Alpes, ESIA DE computer simulation; percolation; grain boundary engineering; boundary network; critical manifold; fracture ID SYSTEMS AB With the development of new, fully three-dimensional metallograpbic techniques, there is considerable interest in characterizing three-dimensional microstructures in ways that go beyond two-dimensional stereology. One characteristic of grain structures is the surface of lowest energy across the microstructure, termed the critical manifold (CM). When the grain boundaries are sufficiently weak, the CM lies entirely on grain boundaries, while when the grain boundaries are strong, cleavage occurs. A scaling theory for the cleavage to intergranular transition of CMs is developed. We find that a critical length scale exists, so that on short length scales cleavage is observed, while at long length scales the CM is rough. CMs for realistic polycrystalline grain structures, determined by it network optimization algorithm, are used to verify the analysis. C1 Sandia Natl Labs, Mat Proc Modeling Dept, Albuquerque, NM 87185 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RP Sandia Natl Labs, Mat Proc Modeling Dept, POB 5800, Albuquerque, NM 87185 USA. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 14 TC 1 Z9 1 U1 0 U2 0 PU TRANS TECH PUBLICATIONS LTD PI DURNTEN-ZURICH PA KREUZSTRASSE 10, 8635 DURNTEN-ZURICH, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1039 EP 1044 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800162 ER PT S AU Janssens, KGF Holm, EA Foiles, SM AF Janssens, KGF Holm, EA Foiles, SM BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Introducing solute drag in irregular cellular automata modeling of grain growth SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, arcelor, Rhone Alpes, ESIA DE microstructure evolution modeling; cellular automata; molecular dynamics; diffusion; solute drag AB In this paper we discuss the principles of a combined approach to solve the problem of solute drag as it occurs in microstructure evolution processes such as grain growth, recrystallization and phase transformation. A recently developed irregular grid cellular automaton. is used to simulate normal grain growth, in which the energy of the grain boundaries is the driving force. A new, discrete diffusion model is used to simulate solute segregation to the grain boundaries. The local concentration of the solute is then taken into account in the calculation of the local grain boundary mobility and/or grain boundary energy, thereby constituting a drag force. The relation between solute concentration and grain boundary mobility/energy is derived from molecular dynamics simulations. C1 Sandia Natl Labs, Mat & Proc Modeling & Comp Dept, Albuquerque, NM 87185 USA. RP Janssens, KGF (reprint author), Sandia Natl Labs, Mat & Proc Modeling & Comp Dept, POB 5800,MS 1411, Albuquerque, NM 87185 USA. RI Janssens, Koenraad/A-1883-2009; Holm, Elizabeth/S-2612-2016; OI Janssens, Koenraad/0000-0001-9776-3431; Holm, Elizabeth/0000-0003-3064-5769; Foiles, Stephen/0000-0002-1907-454X NR 9 TC 3 Z9 3 U1 0 U2 7 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1045 EP 1050 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800163 ER PT S AU Radhakrishnan, B Sarma, GB AF Radhakrishnan, B Sarma, GB BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Simulating the interaction between a straight boundary and a particle SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, arcelor, Rhone Alpes, ESIA DE grain boundary-particle interaction; Potts model; lattice temperature effect AB The paper describes large scale, three-dimensional, Potts model simulations of the interaction between a coarse particle and a straight boundary driven by a bulk stored energy difference across the boundary. It is shown that the variation of the interaction energy as a function of the interface position is significantly affected by the choice of the lattice temperature. The maximum force offered by the particle on the grain boundary decreases with increasing lattice temperature and approaches the theoretical limit at high lattice temperatures. The boundary velocity responds appropriately to changes in the magnitude and direction of the interaction force only at high lattice temperatures. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Radhakrishnan, B (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. NR 6 TC 0 Z9 0 U1 0 U2 2 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1105 EP 1110 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800173 ER PT S AU Budai, JD Yang, M Larson, BC Tischler, JZ Liu, W Weiland, H Ice, GE AF Budai, JD Yang, M Larson, BC Tischler, JZ Liu, W Weiland, H Ice, GE BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI Three-dimensional micron-resolution X-ray Laue diffraction measurement of thermal grain-evolution in aluminum SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, arcelor, Rhone Alpes, ESIA DE microdiffraction; synchrotron x-rays; polychromatic microbeams; three-dimensional grain growth; aluminum ID POLYCRYSTALLINE MATERIALS; SYNCHROTRON-RADIATION; STRUCTURAL MICROSCOPY; GROWTH; RECRYSTALLIZATION; DEFORMATION; SIMULATIONS; PARTICLES AB A new technique for investigating 3D grain growth in polycrystalline materials using white x-ray microdiffraction with micron point-to-point spatial resolution is presented. This technique utilizes focused polychromatic x-rays at the Advanced Photon Source, differential aperture depth-profiling, CCD measurements, and automated analysis of spatially-resolved Laue patterns to measure local lattice structure and orientation. 3D thermal grain growth studies of hot-rolled aluminum have been initiated to demonstrate the capabilities of this method. Complete 3D grain orientation maps were obtained from a hot-rolled aluminum polycrystal. The sample was then annealed to induce grain growth, cooled to room temperature, and re-mapped to measure the thermal migration of all grain boundaries within the same volume region. Initial observations reveal significant grain growth above 360degreesC, involving movement of both low- and high-angle boundaries. Systematic measurements have been obtained of the as-rolled grain structure and of the microstructural evolution after annealing at successively higher temperatures. Small second-phase precipitates have been identified. Such measurements will provide the detailed 3D experimental link needed for testing theories and computer models of 3D grain growth in bulk materials. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Alcoa Tech Ctr, Alcoa Ctr, PA 15069 USA. RP Budai, JD (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM budaijd@ornl.gov; yangw@ornl.gov; larsonbc@ornl.gov; tischlerjz@ornl.gov; liu14@uiuc.edu; weiland_h@atc.alcoa.com; icege@ornl.gov RI Yang, Wenge/H-2740-2012; Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 19 TC 11 Z9 11 U1 1 U2 7 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1373 EP 1378 PN 1-2 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800213 ER PT S AU Nowell, MM Field, DP Wright, SI Lillo, TM AF Nowell, MM Field, DP Wright, SI Lillo, TM BE Bacroix, B Driver, JH LeGall, R Maurice, C Penelle, R Regle, H Tabourot, L TI In-situ EBSD investigation of recrystallization in ECAE processed copper SO RECRYSTALLIZATION AND GRAIN GROWTH, PTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 2nd Joint International Conference on Recrystallization and Grain Growth CY AUG 30-SEP 03, 2004 CL Annecy, FRANCE SP Alcan, Voreppe Res Ctr, Niobium Prod Co GmbH, arcelor, Rhone Alpes, ESIA DE EBSD; OIM; in-situ heating; copper; equal channel angular extrusion ID ORIENTED NUCLEATION; ALUMINUM; TEXTURE; GROWTH AB The microstructural evolution of heavily deformed OFHC copper during recrystallization and grain growth was characterized in-situ by automated Electron Backscatter Diffraction (EBSD) or Orientation Imaging Microscopy (OIM). Successive scans (approximately 50-60 2 minute scans per sample) were performed on samples undergoing heating from ambient temperature to approximately 150-200 degrees C. The orientation and grain boundary textures of growing and shrinking grains are compared. The relationship between various indirect metrics of strain energy and the microstructural evolution are also investigated. These qualitative measures are obtained from OIM data and include parameters such as local misorientation and EBSD pattern quality. C1 EDAX TSL, Draper, UT 84020 USA. Washington State Univ, Pullman, WA 99164 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Nowell, MM (reprint author), EDAX TSL, 392 E 12300 S, Draper, UT 84020 USA. RI Field, David/D-5216-2012; OI Field, David/0000-0001-9415-0795; Lillo, Thomas/0000-0002-7572-7883 NR 8 TC 8 Z9 8 U1 1 U2 8 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 BN 0-87849-952-0 J9 MATER SCI FORUM PY 2004 VL 467-470 BP 1401 EP 1405 PN 1-2 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Crystallography; Materials Science; Metallurgy & Metallurgical Engineering GA BBE29 UT WOS:000225119800218 ER PT S AU van Breugel, W Fragile, C Anninos, P Murray, S AF van Breugel, W Fragile, C Anninos, P Murray, S BE Duc, PA Braine, J Brinks, E TI Jet-induced star formation SO RECYCLING INTERGALACTIC AND INTERSTELLAR MATTER SE IAU SYMPOSIA LA English DT Article; Proceedings Paper CT 217th Symposium of the International-Astronomical-Union on Recycling Intergalactic and Interstellar Matter held at the 25th IAU General Assembly CY AUG 06-10, 2002 CL Sydney, AUSTRALIA ID RADIO GALAXIES; COOLING FLOWS; 4C 41.17; REDSHIFT; HYDRODYNAMICS; ALIGNMENT; EMISSION; COCOONS; CLOUDS AB Jets from radio galaxies can have dramatic effects on the medium through which they propagate. We review observational evidence for jet-induced star formation in low ('FR-I') and high ('FR-II') luminosity radio galaxies, at low and high redshifts respectively. We then discuss numerical simulations which are aimed to explain a jet-induced starburst ('Minkowski's Object') in the nearby FR-I type radio galaxy NGC 541. We conclude that jets can induce star formation in moderately dense (10 cm(-3)), warm (10(4) K) gas; that this may be more common in the dense environments of forming, active galaxies; and that this may provide a mechanism for 'positive' feedback from AGN in the galaxy formation process. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP van Breugel, W (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Murray, Stephen/I-8685-2016 OI Murray, Stephen/0000-0001-5597-090X NR 21 TC 2 Z9 2 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA SN 0074-1809 BN 1-58381-166-4 J9 IAU SYMP PY 2004 IS 217 BP 472 EP 479 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAL43 UT WOS:000222682600120 ER PT S AU Plass, R Baker, MS Walraven, JA AF Plass, R Baker, MS Walraven, JA BE Tanner, DM Ramesham, R TI Electrothermal actuator reliability studies SO RELIABILITY, TESTING AND CHARACTERIZATION OF MEMS/MOEMS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Reliability, Testing, and Characterization of MEM/MOEMS CY JAN 26-28, 2004 CL San Jose, CA SP SPIE AB Shallow V type symmetric electrothermal actuators which have a central shuttle and overall lengths of similar to610 mum, leg widths between 3 and 4.5 mum, and offset angles between 0.7 and 2.3degrees have been subjected to short term, high stress drive currents under different environmental conditions. For all the devices and all test conditions, similar to200 mW power levels lead to plastic deformation both for DC actuation and square wave modulation at the limit of the device's bandwidth. Also, it is noted that under vacuum conditions the hottest portions of the surface roughen significantly and there is significant discoloration of the silicon nitride under the device. SEM analysis of cleaved surfaces of these vacuum actuated devices shows significant near surface pitting. C1 Sandia Natl Labs, Radiat & Reliabil Phys Dept, Albuquerque, NM 87185 USA. RP Plass, R (reprint author), Sandia Natl Labs, Radiat & Reliabil Phys Dept, Albuquerque, NM 87185 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5251-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5343 BP 15 EP 21 DI 10.1117/12.530936 PG 7 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Characterization & Testing; Optics SC Engineering; Materials Science; Optics GA BY73L UT WOS:000189450300003 ER PT S AU Thornberg, SM Zavadil, KR Ohlhausen, JA Keenan, MR Peebles, DE Knorovsky, GA MacCallum, DO Nowak-Neely, BM Abraham, IC Plass, RA AF Thornberg, SM Zavadil, KR Ohlhausen, JA Keenan, MR Peebles, DE Knorovsky, GA MacCallum, DO Nowak-Neely, BM Abraham, IC Plass, RA BE Tanner, DM Ramesham, R TI Unified characterization of surfaces and gases in MEMS devices SO RELIABILITY, TESTING AND CHARACTERIZATION OF MEMS/MOEMS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Reliability, Testing, and Characterization of MEM/MOEMS CY JAN 26-28, 2004 CL San Jose, CA SP SPIE DE MEMS; TOF-SIMS; dormancy; aging; lateral force microscopy; LFM; multivariate; gas; mass spectroscopy; occluded volume ID SELF-ASSEMBLED MONOLAYERS; DEPOSITION; STICTION AB Chemical and physical materials-aging processes can significantly degrade the long-term performance reliability of dormant microsystems. This degradation results from materials interactions with the evolving microenvironment by changing both bulk and interfacial properties (e.g., mechanical and fatigue strength, interfacial friction and stiction, electrical resistance). Eventually, device function is clearly threatened and as such, these aging processes are considered to have the potential for high (negative) consequences. Sandia National Laboratories is developing analytical characterization methodologies for identifying the chemical constituents of packaged microsystem enviromnents, and test structures for proving these analytical techniques. To accomplish this, we are developing a MEMS test device containing structures expected to exhibit dormancy/analytical challenges, extending the range of detection for a series of analytical techniques, merging data from these separate techniques for greater information return, and developing methods for characterizing the internal atmosphere/gases. Surface analyses and data extraction have been demonstrated on surfaces of various geometries with different SAMS coatings, and gas analyses on devices with internal free volumes of 3 microliters have also been demonstrated. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Thornberg, SM (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 9 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5251-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5343 BP 186 EP 193 DI 10.1117/12.524777 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Characterization & Testing; Optics SC Engineering; Materials Science; Optics GA BY73L UT WOS:000189450300023 ER PT S AU Chandross, M Grest, GS Stevens, MJ Webb, EB AF Chandross, M Grest, GS Stevens, MJ Webb, EB BE Tanner, DM Ramesham, R TI Defects and friction in alkylsilane self-assembled monolayers SO RELIABILITY, TESTING AND CHARACTERIZATION OF MEMS/MOEMS III SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd Conference on Reliability, Testing, and Characterization of MEM/MOEMS CY JAN 26-28, 2004 CL San Jose, CA SP SPIE DE self-assembled monolayers; friction; alkylsilanes ID MOLECULAR-DYNAMICS; FORCE-FIELD; SIMULATION AB The adhesion and friction between pairs of self-assembled monolayers (SAMs) of alkylsilane chains on a silicon dioxide surface are studied using molecular dynamics simulations. We study chains with n=6, 8, 12, and 18 carbons in the backbone for both fully packed and defected monolayers. The defects are introduced by the random removal of chains from a well-ordered crystalline substrate. The adhesion force between monolayers at a given separation is found to increase monotonically with chain length and with coverage for a fixed chain length for the crystalline substrate. Friction simulations were performed at a relative shear velocity of 2 m/s at constant applied loads between 200 and 600 MPa. Stick slip motion is observed at full coverage, but disappears with the inclusion of 10% defects. We find that with the addition of random defects, the friction becomes insensitive to both chain length and defect density. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chandross, M (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. NR 12 TC 1 Z9 1 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5251-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5343 BP 207 EP 214 DI 10.1117/12.524562 PG 8 WC Engineering, Electrical & Electronic; Engineering, Mechanical; Materials Science, Characterization & Testing; Optics SC Engineering; Materials Science; Optics GA BY73L UT WOS:000189450300025 ER PT S AU Balick, LK Rodger, AP Clodius, WB AF Balick, LK Rodger, AP Clodius, WB BE Owe, M DUrso, G Moreno, JF Calera, A TI Multispectral thermal imager land surface temperature retrieval framework SO REMOTE SENSING FOR AGRICULTURE, ECOSYSTEMS, AND HYDROLOGY V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing for Agriculture, Ecosystems and Hydrology V CY SEP 08-10, 2003 CL Barcelona, SPAIN SP SPIE DE satellite land surface temperature retrieval AB This paper presents a framework for earth surface temperature retrievals from Multispectral thermal images acquired buy the US Dept. of Energy Multispectral Thermal Imager (MTI) satellite. The satellite has 15 spectral band including 5 bands in the thermal IR. Also there are three near IR bands for daytime retrieval of atmospheric water vapor to use for atmospheric compensation of the thermal IR measurements. Multispectral thermal IR techniques for retrieval of water surface temperature from MTI data have been implemented and made operational. The approach to temperature retrieval presented is amenable to land surface as well as water surface temperature retrievals. The approach uses the best available atmospheric profiles of temperature and humidity as inputs to MODTRAN4 to compute look up tables of the necessary atmospheric radiative transfer components. These profiles can come from any source but we make extensive use of grided data assimilation products for numerical weather prediction. For daytime images, the humidity profiles are scaled by the column water vapor retrieved from near IR bands on a pixel-by-pixel basis. Ground leaving radiance images can then be produced and apparent temperatures are computed given some source of emissivity information. To date, we have implemented the Normalized Emissivity Method (NEM) and the ASTER temperature emissivity separation approach adapted to MTI, and the ASTER and MODIS spectral libraries are available. A final retrieved temperature is determined from the temperatures retrieved for each band according to a specified rule. Validation of the techniques is presented for one water site and two land sites where the spectral emissivity is known and simultaneous ground measurements of skin temperatures were made. The daytime retrieval results are within 1.1C of the ground measurements. Finally, we investigate the impact or using different global weather data products as the meteorological data source. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87545 USA. RP Balick, LK (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, M-S B244,POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5115-0 J9 P SOC PHOTO-OPT INS PY 2004 VL 5232 BP 499 EP 509 DI 10.1117/12.512745 PG 11 WC Agriculture, Multidisciplinary; Environmental Sciences; Remote Sensing; Water Resources SC Agriculture; Environmental Sciences & Ecology; Remote Sensing; Water Resources GA BY77H UT WOS:000189459600049 ER PT S AU Genkova, I Long, C Besnard, T Gillotay, D AF Genkova, I Long, C Besnard, T Gillotay, D BE Schafer, KP Comeron, A Carleer, MR Picard, RH Sifakis, NI TI Assessing cloud spatial and vertical distribution with cloud infrared radiometer CIR-7 SO REMOTE SENSING OF CLOUDS AND THE ATMOSPHERE IX SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Remote Sensing of Clouds and the Atmosphere IX CY SEP 13-15, 2004 CL Maspalomas, SPAIN SP SPIE, Soc Espanola Opt, NASA, European Opt Soc DE cloud amount; infrared; vertical cloud distribution; cloud map; ground-based; remote sensing AB Recently developed, the Cloud Infrared Radiometer CIR-7, operates 7 infrared sensors, each with a 6-degree field of view, and spectral range 8-14 pm. The sensors are mounted on a semi-circular band at angles 0, 12, 24, 36, 48, 60 and 72degrees. A "hemispherical" mosaic of 181 brightness temperature measurements centered on the zenith is obtained by the rotation of the band around the vertical axis, performing 30 scans, every 12degrees from 0degrees (North) to 348degrees. We present an algorithm that utilizes the brightness temperatures from the CIR-7 given the precipitable water vapor amounts and vertical profiles of the thermodynamic state of the atmosphere from independent measurements. It estimates the total cloud amount, the amount of low, middle and high clouds, maps out the spatial distribution of the cloud field and determines the vertical distribution of the clouds by computing cloud base heights. The algorithm is validated through comparisons with well studied ground-based and satellite retrieval techniques. Initial analyses show good cloud amount assessment and spatial mapping abilities. The estimated mean absolute cloud amount difference for day time is 12.3% when compared to the amount of opaque clouds derived with a total sky imager (TSI). For night time, this difference is 19.4% comparing to the effective cloud fraction derived with an atmospheric emitted radiance interferometer (AERI). The vertical distribution understanding is currently limited; however, the amounts of low, middle and high clouds could be determined and studied further. C1 Pacific NW Natl Lab, Richland, WA 98208 USA. RP Genkova, I (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd, Richland, WA 98208 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5518-0 J9 P SOC PHOTO-OPT INS PY 2004 VL 5571 BP 1 EP 10 DI 10.1117/12.564234 PG 10 WC Remote Sensing SC Remote Sensing GA BBN01 UT WOS:000226252700001 ER PT S AU Maly, K Nelson, M Zubair, M Amrou, A Kothamasa, S Wang, L Luce, R AF Maly, K Nelson, M Zubair, M Amrou, A Kothamasa, S Wang, L Luce, R BE Heery, R Lyon, L TI Enhancing Kepler usability and performance SO RESEARCH AND ADVANCED TECHNOLOGY FOR DIGITAL LIBRARIES SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 8th European Conference on Research and Advanced Technology for Digital Libraries (ECDL 2004) CY SEP 12-17, 2004 CL Univ Bath, Bath, ENGLAND SP Informat Syst Comm HO Univ Bath AB Kepler is an attempt to bridge the gap between established, organization-backed digital libraries and groups of researchers that wish to publish their findings under their control, anytime, anywhere yet have the advantages of an OAl-compliant digital library. We describe an architecture and implementation of the Kepler system that allows an archivelet to be installed in the order of minutes by an author on a personal machine and a group server in less than an hour. The group server will harvest from all archivelets and make the union of all published papers available for search to a community. We describe how a group administrator can provide an XML schema for the metadata and how the Kepler engine will validate against them when an author publishes a paper and completes the metadata. We have demonstrated that we can surmount the technical difficulties for authors to publish as easy as to a website yet produce OAl-compliant digital libraries. C1 Old Dominion Univ, Comp Sci Dept, Norfolk, VA 23529 USA. Los Alamos Natl Lab, Res Lib, Los Alamos, NM 87544 USA. RP Old Dominion Univ, Comp Sci Dept, Norfolk, VA 23529 USA. EM maly@cs.odu.edu; mln@cs.odu.edu; zubair@cs.odu.edu; aamr@cs.odu.edu; kumar_s@cs.odu.edu; wang_l@cs.odu.edu; rick.luce@lanl.gov OI Nelson, Michael/0000-0003-3749-8116 NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-23013-0 J9 LECT NOTES COMPUT SC PY 2004 VL 3232 BP 317 EP 328 PG 12 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BAX48 UT WOS:000224092600029 ER PT B AU Quarry, MJ AF Quarry, MJ BE Thompson, DO Chimenti, DE TI Guided wave inspection of multi-layered structures SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 23A AND 23B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 30th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 27-AUG 01, 2003 CL Green Bay, WI SP Iowa State Univ, Ctr Nondestruct Evaluat, QNDE Programs AB This study investigates the utilization of guided waves for inspecting structures that consist of multiple layers. Advances have been made in recent years using guided waves to inspect single layer structures, such as pipes, tubes, and aircraft structures. Multi-layered structures present many new aspects to guided wave propagation. A theoretical understanding of what modes exist, how do the modes behave, and what factors influence them needs to be acquired for many applications. Experiments must be carried out to evaluate potential for practical applications. Examples of practical applications include coated pipes, composites, diffusion bonded aircraft structures, and microelectronic structures. This work is a fundamental study of ultrasonic guided waves in multi-layered plates. Experiments were conducted on multi-layered plates to demonstrate defect detection in layer of interest of a multi-layered structure by preferentially exciting modes with sufficient energy in that layer. Analysis of the dispersion curves show that some modes are more attractive candidates than others based on their displacements and energy distribution across the structure. Experimental results show that sweeping frequency and phase velocity can be performed to find suitable modes for inspecting a layer of interest for a given multi-layered structure. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Quarry, MJ (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 7 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0173-X J9 REV PROG Q PY 2004 VL 23 BP 246 EP 253 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Imaging Science & Photographic Technology SC Acoustics; Engineering; Materials Science; Imaging Science & Photographic Technology GA BY96D UT WOS:000189505300030 ER PT B AU Sun, JG Erdman, S AF Sun, JG Erdman, S BE Thompson, DO Chimenti, DE TI Effect of finite flash duration on thermal diffusivity imaging of high-diffussivity or thin materials SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 23A AND 23B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 30th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 27-AUG 01, 2003 CL Green Bay, WI SP Iowa State Univ, Ctr Nondestruct Evaluat, QNDE Programs AB Thermal diffusivity imaging has been widely used as a nondestructive evaluation technique for characterizing structural components and detecting defects. The accuracy of the diffusivity calculations depends on several experimental parameters. While most of the parameters can be controlled to within acceptable range, finite flash duration is the dominant parameter affecting the accuracy for high-diffusivity or thin materials. In this study, a new theoretical formulation is developed to correct the finite flash duration of typical photographic flash lamps. Experimental results showed that the formulation determines the correct diffusivity of a thin graphite and a high-diffusivity ScD composite sample. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Sun, JG (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0173-X J9 REV PROG Q PY 2004 VL 23 BP 482 EP 487 PN A&B PG 6 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Imaging Science & Photographic Technology SC Acoustics; Engineering; Materials Science; Imaging Science & Photographic Technology GA BY96D UT WOS:000189505300060 ER PT B AU Reverdy, F Hopkins, D AF Reverdy, F Hopkins, D BE Thompson, DO Chimenti, DE TI Inspection of spot welds using an ultrasonic phased array SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 23A AND 23B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 30th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 27-AUG 01, 2003 CL Green Bay, WI SP Iowa State Univ, Ctr Nondestruct Evaluat, QNDE Programs AB Results are summarized for a series of experiments in which several hundred spot welds were inspected using high-frequency phased-array ultrasonic probes. Analysis of the signals in the Fourier domain allows identification of satisfactory, undersized and defective welds. Work is underway to develop analysis techniques that will allow dimensional analysis of the welds. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Reverdy, F (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 46A-1123, Berkeley, CA 94720 USA. NR 8 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0173-X J9 REV PROG Q PY 2004 VL 23 BP 801 EP 808 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Imaging Science & Photographic Technology SC Acoustics; Engineering; Materials Science; Imaging Science & Photographic Technology GA BY96D UT WOS:000189505300101 ER PT B AU Ahmed, S Panetta, PD Hockey, RL AF Ahmed, S Panetta, PD Hockey, RL BE Thompson, DO Chimenti, DE TI Effects of layer properties on the ultrasonic resonance of composite spheres SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 23A AND 23B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 30th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 27-AUG 01, 2003 CL Green Bay, WI SP Iowa State Univ, Ctr Nondestruct Evaluat, QNDE Programs AB The efficient calculation of the resonance frequencies is required for the effective application of resonant ultrasound spectroscopy (RUS) to determine the relevant properties of an elastic object. If a suitable number of the resonance frequencies of an elastic object are known, in principle, one can deduce a number of its physical proper-ties like elastic constants, density, dimensions, shape, etc. However, general analytic expressions are not available for the normal mode free vibrations of a body with arbitrary shape and elastic properties. It was noticed by Holland and Demarest (1971) that a simple variational principle can be applied to compute the normal mode frequencies of an elastic body with free boundaries. Based on this variational method, Visscher et al. (1991) developed the XYZ algorithm which can be applied to compute the resonance frequencies of a body with arbitrary shape and elastic properties. Since layered systems are finding increasing use in engineering applications, computational studies are being carried out to investigate the suitability of RUS as an NDE technique to determine imperfections in a layered system. Specifically, the normal mode frequencies of a four-layered sphere are computed by the XYZ algorithm. It will be shown that the deviations from specified layer properties cause noticeable shifts on the resonant frequencies. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Ahmed, S (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,POB 999,MSIN K5-26, Richland, WA 99352 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0173-X J9 REV PROG Q PY 2004 VL 23 BP 930 EP 936 PN A&B PG 7 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Imaging Science & Photographic Technology SC Acoustics; Engineering; Materials Science; Imaging Science & Photographic Technology GA BY96D UT WOS:000189505300117 ER PT B AU Hopkins, D Reverdy, F AF Hopkins, D Reverdy, F BE Thompson, DO Chimenti, DE TI Model for deformation, stress and contact at interfaces - Implications for ultrasonic measurements SO REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION, VOLS 23A AND 23B SE REVIEW OF PROGRESS IN QUANTITATIVE NONDESTRUCTIVE EVALUATION LA English DT Proceedings Paper CT 30th Annual Review of Progress in Quantitative Nondestructive Evaluation CY JUL 27-AUG 01, 2003 CL Green Bay, WI SP Iowa State Univ, Ctr Nondestruct Evaluat, QNDE Programs ID ROUGH SURFACES AB An analytical model is presented for calculating deformation, contact area, stiffness, and the distribution of stress across joints and interfaces that can be described as two rough surfaces in partial contact. Analytical, modeling, and experimental results are presented that demonstrate the role that deformation of the bulk material surrounding the joint and mechanical interaction between contact points play in joint properties and the propagation of acoustic waves across the interface. Results are applied to help interpret C-scans of spot-welded joints. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Hopkins, D (reprint author), Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 46A-1123, Berkeley, CA 94720 USA. NR 16 TC 1 Z9 1 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0173-X J9 REV PROG Q PY 2004 VL 23 BP 952 EP 959 PN A&B PG 8 WC Acoustics; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Imaging Science & Photographic Technology SC Acoustics; Engineering; Materials Science; Imaging Science & Photographic Technology GA BY96D UT WOS:000189505300120 ER PT J AU Saes, M Bressler, C van Mourik, F Gawelda, W Kaiser, M Chergui, M Bressler, C Grolimund, D Abela, R Glover, TE Heimann, PA Schoenlein, RW Johnson, SL Lindenberg, AM Falcone, RW AF Saes, M Bressler, C van Mourik, F Gawelda, W Kaiser, M Chergui, M Bressler, C Grolimund, D Abela, R Glover, TE Heimann, PA Schoenlein, RW Johnson, SL Lindenberg, AM Falcone, RW TI A setup for ultrafast time-resolved x-ray absorption spectroscopy SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID AREA AVALANCHE PHOTODIODES; LASER; DYNAMICS; PUMP AB We present a setup which allows the measurement of time-resolved x-ray absorption spectra with picosecond temporal resolution on liquid samples at the Advanced Light Source at Lawrence Berkeley National Laboratories. The temporal resolution is limited by the pulse width of the synchrotron source. We characterize the different sources of noise that limit the experiment and present a single-pulse detection scheme. (C) 2004 American Institute of Physics. C1 Univ Lausanne, IPMC BSP, CH-1015 Lausanne, Switzerland. Paul Scherrer Inst, Nucl Energy & Safety Res Dept, CH-5232 Villigen, Switzerland. Swiss Light Source, CH-5232 Villigen, Switzerland. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Bressler, C (reprint author), Univ Lausanne, IPMC BSP, CH-1015 Lausanne, Switzerland. EM christian.bressler@ipmc.unil.ch RI Bressler, Christian/G-1864-2010; Johnson, Steven/B-3252-2008; Gawelda, Wojciech/B-7878-2014; Schoenlein, Robert/D-1301-2014 OI Johnson, Steven/0000-0001-6074-4894; Gawelda, Wojciech/0000-0001-7824-9197; Schoenlein, Robert/0000-0002-6066-7566 NR 19 TC 75 Z9 75 U1 1 U2 20 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 2004 VL 75 IS 1 BP 24 EP 30 DI 10.1063/1.1633003 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 757EU UT WOS:000187536500003 ER PT J AU Pereira, NR Dufresne, EM Clarke, R Arms, DA AF Pereira, NR Dufresne, EM Clarke, R Arms, DA TI Parabolic lithium refractive optics for x rays SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LENSES; METAL AB Excellent x-ray optics for photons at around 10 keV can be expected with lithium metal. One of the best compound refractive lens designs [Lengeler , J. Appl. Phys. 84, 5855 (1998)] is now produced routinely in aluminum, and more recently has been demonstrated using beryllium [M. Kuhlmann (unpublished)]. Here, we report a similar refractive lens made from lithium. At 10.87 keV, this lens has a similar or equal to2 m focal length, more than 90% peak transmission, and an average transmission of 49%. The lens shows a very useful gain of up to 40. The full widths at half maximum (FWHM) of the focus are blurred by roughly 20 mum, resulting in a horizontal and vertical FWHM of 33 and 17 mum for an image distance of 2.13 m. The lens produces speckle on the x-ray beam, which is likely due to the inhomogeneities of the lens surface: Coherent x-ray scattering is useful in understanding imperfections in x-ray optics, such as mirrors and lenses. Better molding techniques should result in improved performance and enable microbeam techniques with this type of Li lens. (C) 2004 American Institute of Physics. C1 Ecopulse Inc, Springfield, VA 22150 USA. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. Univ Michigan, MHATT CAT, Ann Arbor, MI 48109 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. MHATT CAT, Argonne, IL 60439 USA. RP Pereira, NR (reprint author), Ecopulse Inc, POB 528, Springfield, VA 22150 USA. NR 26 TC 18 Z9 18 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 2004 VL 75 IS 1 BP 37 EP 41 DI 10.1063/1.1633007 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 757EU UT WOS:000187536500005 ER PT J AU Combs, SK Foust, CR Gouge, MJ AF Combs, SK Foust, CR Gouge, MJ TI Fast-opening, high-throughput gas valve and application for inertial fusion energy R&D SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID INJECTION AB A fast-opening, high-throughput gas valve and its application to inertial fusion energy (IFE) research and development are described. The valve is a pilot type with two stages of active components. The pilot or first stage section is magnetically driven and equipped with a 4.2-mm-diam orifice. The pilot valve is energized to initiate operations and dumps gas from the upstream section of the second stage to the main valve outlet, and the resultant pressure differential across the large (22.3-mm-diam) output orifice seat causes mechanical activation of the second stage. Both stages are equipped with hard polyimide stem tips and springs for sealing. The valve has been operated reliably with helium gas at pressures in the range of 4-35 bar and frequencies up to 6 Hz, with maximum flow rates of approximate to10(6) Torr l/s. The valve was developed to provide helium propellant gas for accelerating IFE targets to speeds up to 400 m/s in an experimental injector system under construction by General Atomics. (C) 2004 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Combs, SK (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM combssk@ornl.gov NR 4 TC 8 Z9 8 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JAN PY 2004 VL 75 IS 1 BP 270 EP 272 DI 10.1063/1.1633026 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 757EU UT WOS:000187536500039 ER PT J AU Coutant, CC AF Coutant, CC TI A riparian habitat hypothesis for successful reproduction of white sturgeon SO REVIEWS IN FISHERIES SCIENCE LA English DT Review DE Acipenser transmontanus; recruitment; egg attachment; larval habitat ID LOWER COLUMBIA-RIVER; SAN-JOAQUIN ESTUARY; ACIPENSER-TRANSMONTANUS; LAKE STURGEON; ONTOGENIC BEHAVIOR; SPAWNING HABITAT; FRASER-RIVER; LIFE-HISTORY; SNAKE RIVER; ARTIFICIAL PROPAGATION AB White sturgeon (Acipenser transmontanus) has recruitment failure or severe interannual variability in much of its range. Exceptions are Columbia River below Bonneville Dam, Snake River below Hells Canyon Dam, lower Fraser River, and Sacramento River. Since rivers were impounded or flows regulated, once-continuous populations now isolated by natural barriers or dams often have not reproduced successfully, despite successful spawning events. Research has not adequately explained recruitment failures or why certain populations are successful. This paper proposes that submerged riparian habitat during seasonal high water is needed for early development. Where recruitment is successful, channels are complex and floodable riparian vegetation or rocky substrate is abundant. There, spawning occurs in turbulent zones Upstream (1-5 km) of seasonally submerged riparian habitat, eggs can disperse into inundated habitat and adhere to newly wetted surfaces for incubation, yolk-sac larvae can move to riparian crevices for prefeeding development, feeding larvae have food-rich flooded habitat for early growth, and larvae can transition to juveniles as water recedes to permanent channels. Such habitat is lacking where recruitment is low and present only in high-flow years where recruitment is sporadic. These observations suggest that management should rehabilitate riparian zones and provide high river flows during spawning to stimulate natural recruitment. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Coutant, CC (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM CoutantCC@ornl.gov NR 152 TC 34 Z9 37 U1 2 U2 18 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1064-1262 EI 1547-6553 J9 REV FISH SCI JI Rev. Fish. Sci. PY 2004 VL 12 IS 1 BP 23 EP 73 DI 10.1080/10641260490273023 PG 51 WC Fisheries SC Fisheries GA 780CW UT WOS:000189354600002 ER PT J AU Dine, M Kusenko, A AF Dine, M Kusenko, A TI Origin of the matter-antimatter asymmetry SO REVIEWS OF MODERN PHYSICS LA English DT Review ID ELECTROWEAK PHASE-TRANSITION; SUPERSYMMETRIC STANDARD MODEL; FLAT-DIRECTION BARYOGENESIS; NUMBER NON-CONSERVATION; SCALAR FIELD THEORIES; Q-BALLS; DARK-MATTER; BARYON ASYMMETRY; NONTOPOLOGICAL SOLITONS; EARLY UNIVERSE AB Although the origin of matter-antimatter asymmetry remains unknown, continuing advances in theory and improved experimental limits have ruled out some scenarios for baryogenesis, for example, sphaleron baryogenesis at the electroweak phase transition in the Standard Model. At the same time, the success of cosmological inflation and the prospects for discovering supersymmetry at the Large Hadron Collider have put some other models in sharper focus. We review the current state of our understanding of baryogenesis with emphasis on those scenarios that we consider most plausible. C1 Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. RP Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. NR 167 TC 181 Z9 181 U1 3 U2 16 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 EI 1539-0756 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JAN PY 2004 VL 76 IS 1 BP 1 EP 30 PG 30 WC Physics, Multidisciplinary SC Physics GA 800AN UT WOS:000220001400001 ER PT J AU Endres, RG Cox, DL Singh, RRP AF Endres, RG Cox, DL Singh, RRP TI Colloquium: The quest for high-conductance DNA SO REVIEWS OF MODERN PHYSICS LA English DT Review ID CURRENT-VOLTAGE CHARACTERISTICS; RANGE ELECTRON-TRANSFER; NUCLEOTIDE BASE-STACKS; CHARGE MIGRATION; MOLECULAR WIRE; B-DNA; DOUBLE HELIX; LAMBDA-DNA; LARGE SYSTEMS; TRANSPORT AB The DNA molecule, well known from biology for containing the genetic code of all living species, has recently caught the attention of chemists and physicists. A major reason for this interest is DNA's potential use in nanoelectronic devices, both as a template for assembling nanocircuits and as an element of such circuits. Without question, a truly conducting form of DNA would have a major impact on developments in nanotechnology. It has also been suggested that extended electronic states of DNA could play an important role in biology, e.g., through the processes of DNA damage sensing or repair or through long-range charge transfer. However, the electronic properties of DNA remain very controversial. Charge-transfer reactions and conductivity measurements show a large variety of possible electronic behavior, ranging from Anderson and band-gap insulators to effective molecular wires and induced superconductors. Indeed, understanding the conductance of a complicated polyelectrolytic aperiodic system is by itself a major scientific problem. In this Colloquium, the authors summarize the wide-ranging experimental and theoretical results and look for any consistencies between them. They also pose simple questions regarding the electronic states of DNA within the framework of generalized Huckel and Slater-Koster theories. The Colloquium provides a quantitative overview of DNA's electronic states as obtained from density-functional theory, focusing on dependence on structure, on molecular stretching and twisting, and on water and counterions. While there is no clear theoretical basis for truly metallic DNA, situations are discussed in which very small energy gaps might arise in the overall DNA/water/counterion complex, leading to thermally activated conduction at room temperature. C1 Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Univ Calif Davis, Dept Phys, Ctr Biophoton Sci & Technol, Davis, CA 95616 USA. RP Endres, RG (reprint author), Oak Ridge Natl Lab, Ctr Computat Sci, Oak Ridge, TN 37831 USA. NR 113 TC 543 Z9 560 U1 4 U2 78 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0034-6861 J9 REV MOD PHYS JI Rev. Mod. Phys. PD JAN PY 2004 VL 76 IS 1 BP 195 EP 214 DI 10.1103/RevModPhys.76.195 PG 20 WC Physics, Multidisciplinary SC Physics GA 800AN UT WOS:000220001400005 ER PT S AU Beitel, GA Gertman, DI Plum, MM AF Beitel, GA Gertman, DI Plum, MM BE Brebbia, CA TI Balanced scorecard method for predicting the probability of a terrorist attack SO RISK ANALYSIS IV SE MANAGEMENT INFORMATION SYSTEMS LA English DT Proceedings Paper CT 4th International Conference on Computer Simulation in Risk Analysis and Hazard Mitigation CY SEP 27-29, 2004 CL Rhodes, GREECE DE quantitative risk assessment; QTRIM; SAPHIRE; balanced scorecard; terrorist targeting strategies; probabilities of attack AB A research and development project at the Idaho National Engineering and Environmental Laboratory (INEEL) built and tested a quantitative threat-risk index model (QTRIM) to predict the risk of a terrorist attack against a national infrastructure. A key component of the threat-risk index model, the "targeting model", estimates the probability of a terrorist attack. This paper describes that targeting model. In general, risk from a terrorist attack is calculated as the product of an attack's probability by probable damage. Defence strategists often assume that a probability of attack is impossible to predict and assign a value of one (a chance of certainly), in which case "risk assessment" is reduced to "vulnerability assessment." In other cases, defense strategists may assume qualitative vulnerability measures such as high, low, or medium. Our research selected a quantitative approach where risk is calculated using terrorist specific constraints, objectives, value systems, logistics, and opportunities within a business decision framework of a balanced scorecard. QTRIM was exercised on a limited data set of terrorist organizations: Al-Qaida and the Earth Liberation Front. Specific to INEEL's research, the nation's inventory of infrastructure was evaluated on a macroeconomic level, which was then followed by an evaluation of a specific infrastructure sector. Resulting probabilities were compared to historical terrorist attack data with sufficiently accurate results to warrant further studies and model improvements. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. RP Beitel, GA (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID USA. NR 11 TC 2 Z9 2 U1 0 U2 1 PU WIT PRESS PI SOUTHAMPTON PA ASHURST LODGE, SOUTHAMPTON SO40 7AA, ASHURST, ENGLAND SN 1470-6326 BN 1-85312-736-1 J9 MANAG INFORMAT SYST PY 2004 VL 9 BP 581 EP 592 PG 12 WC Engineering, Multidisciplinary; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA BBN81 UT WOS:000226374700053 ER PT J AU Barenblatt, GI AF Barenblatt, GI TI Turbulent boundary layers at very large Reynolds numbers SO RUSSIAN MATHEMATICAL SURVEYS LA English DT Article ID PRESSURE-GRADIENT; MODEL; WAKE AB Andrei Nikolaevich Kolmogorov firmly believed that in the absence of a rigorous self-contained theory of turbulent fluids and gases one must use hypotheses obtained by processing experimental data. This paper begins with a discussion of the hypothesis of complete self-similarity used in the proof of the widely known (Reynolds-number independent) von Karman-Prandtl logarithmic law for the distribution of velocity in a turbulent shear flow. It is shown that this hypothesis has not been confirmed experimentally. Instead, a hypothesis of incomplete self-similarity is proposed which leads to a power-law dependence on the Reynolds number. It is shown that this law agrees well with experiments for the most important classes of turbulent shear flows (for flows in pipes and boundary layers). C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst Oceanol, Moscow 117901, Russia. RP Barenblatt, GI (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. NR 27 TC 3 Z9 3 U1 0 U2 2 PU LONDON MATHEMATICAL SOCIETY RUSSIAN ACAD SCIENCES PI LETCHWORTH PA C/O TURPION LTD, TURPIN DISTRIBUTION SERVICES, BLACKHORSE RD,, LETCHWORTH SG6 1HN, HERTS, ENGLAND SN 0036-0279 J9 RUSS MATH SURV+ JI Russ. Math. Surv. PD JAN-FEB PY 2004 VL 59 IS 1 BP 47 EP 64 DI 10.1070/RM2004v059n01ABEH000700 PG 18 WC Mathematics SC Mathematics GA 832WM UT WOS:000222298300004 ER PT J AU Ackermann, S Kunz, M Armbruster, T Schefer, J Hanni, H AF Ackermann, S Kunz, M Armbruster, T Schefer, J Hanni, H TI Cation distribution in a Fe-bearing K-feldspar from Itrongay, Madagascar: A combined neutron- and X-ray single-crystal diffraction study SO SCHWEIZERISCHE MINERALOGISCHE UND PETROGRAPHISCHE MITTEILUNGEN LA English DT Article DE K-feldspars; single-crystal X-ray diffraction; neutron diffraction ID ORDER-DISORDER; FE-3+ IONS; SANIDINE; ALBITE AB We determined the cation distribution and ordering of Si, Al and Fe on the tetrahedral sites of a monoclinic low-sanidine from Itrongay, Madagascar, by combined neutron- and X-ray single-crystal diffraction. The cation distribution was determined by means of a simultaneous refinement using neutron- and X-ray data, as well as by combining scattering densities obtained from separate refinements with chemical data from a microprobe experiment. The two methods give the same results and show that Fe is fully ordered on T1, whereas Al shows a high degree of disorder. Based on this result and previously published temperature-dependent X-ray data, we conclude that it is preferential ordering of Fe on T1 even at high temperature, rather than high diffusion kinetics of Fe, which causes this asymmetry in ordering behaviour between Al and Fe. The preferential ordering of Fe relative to Al is in line with its 25 percent larger ionic radius. C1 Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, ALS, Berkeley, CA 94720 USA. Univ Basel, Dept Earth Sci, CH-4056 Basel, Switzerland. Univ Bern, Lab Chem & Mineral Crystallog, CH-3012 Bern, Switzerland. ETH, Neutron Scattering Lab, CH-5232 Villigen, Switzerland. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Swiss Gemmol Inst, CH-4001 Basel, Switzerland. RP Kunz, M (reprint author), Univ Calif Berkeley, Dept Earth & Planetary Sci, Berkeley, CA 94720 USA. EM mkunz@lbl.gov RI Schefer, Jurg/G-3960-2012; Kunz, Martin/K-4491-2012; OI Kunz, Martin/0000-0001-9769-9900; Ackermann Krzemnicki, Sonia/0000-0002-0187-1188; Armbruster, Thomas/0000-0002-9586-2097 NR 23 TC 5 Z9 5 U1 0 U2 2 PU STAUBLI VERLAG AG PI ZURICH PA POSTFACH 566, CH-8045 ZURICH, SWITZERLAND SN 0036-7699 J9 SCHWEIZ MINER PETROG JI Schweiz. Mineral. Petrogr. Mitt. PY 2004 VL 84 IS 3 BP 345 EP 354 PG 10 WC Geology; Mineralogy SC Geology; Mineralogy GA 034UB UT WOS:000236955000008 ER PT J AU Babu, SS David, SA Park, JW Vitek, JM AF Babu, SS David, SA Park, JW Vitek, JM TI Joining of nickel base superalloy single crystals SO SCIENCE AND TECHNOLOGY OF WELDING AND JOINING LA English DT Article; Proceedings Paper CT Conference on Microstructure and Performance of Joints in High Temperature Alloys CY NOV 20, 2002 CL London, ENGLAND SP Inst Mat DE computational weldability; nickel alloys; single crystal superalloys; solidification grain structure ID FIELD-ION MICROSCOPY; ELECTRON-BEAM WELDS; SOLIDIFICATION; MICROSTRUCTURES; SYSTEM; GROWTH; MAPS AB The paper reviews scientific and technological issues related to repair weldability of nickel base single crystal superalloys. The role of weld pool geometry and crystallographic orientation of the single crystals on the solidification grain structure was discussed. Results of asymmetric cracking during welding of thin crystals due to stray grain formation were introduced, The role of high resolution characterisation tools including electron microscopy and atom probe field ion microscopy in understanding non-equilibrium microstructure evolution was demonstrated. Computational methodologies to describe the dynamic thermal, stress and microstrutural evolutions to describe weldability as well as the performance of these welds were discussed. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Babu, SS (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 33 TC 21 Z9 22 U1 5 U2 22 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 1362-1718 J9 SCI TECHNOL WELD JOI JI Sci. Technol. Weld. Join. PD JAN PY 2004 VL 9 IS 1 BP 1 EP 12 DI 10.1179/136217104225017080 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 811QP UT WOS:000220786700001 ER PT J AU Park, JW Vitek, JM Babu, SS David, SA AF Park, JW Vitek, JM Babu, SS David, SA TI Stray grain formation, thermomechanical stress and solidification cracking in single crystal nickel base superalloy welds SO SCIENCE AND TECHNOLOGY OF WELDING AND JOINING LA English DT Article DE stray grains; single crystal; crack AB In the present study, the effects of stray grain formation and thermomechanical stresses on solidification cracking in welds of single crystal Ni-base superalloys have been investigated. Welds were made in an asymmetric crystallographic orientation under three different processing conditions. As welding speed and power increased, stray grain formation became extensive, but only on one side of the weld. Solidification cracking also became more extensive and occurred mostly along the stray grain boundaries. The three welding processes have been simulated using the finite element method (FEM). The calculation results showed that thermomechanical stresses increase with welding speed and power, leading to increased susceptibility to cracking. These results agree well with experimental observations. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Park, JW (reprint author), Samsung Eectromech, Suwon, South Korea. EM jinwoo09.park@samsung.com RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 16 TC 17 Z9 17 U1 2 U2 17 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 1362-1718 J9 SCI TECHNOL WELD JOI JI Sci. Technol. Weld. Join. PY 2004 VL 9 IS 6 BP 472 EP 482 DI 10.1179/136217104225021841 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 890GU UT WOS:000226500500001 ER PT S AU Hanushevsky, A Stockinger, H AF Hanushevsky, A Stockinger, H BE Herrero, P Perez, MA Robles, V TI A proxy service for the xrootd data server SO SCIENTIFIC APPLICATIONS OF GRID COMPUTING SE Lecture Notes in Computer Science LA English DT Article; Proceedings Paper CT 1st International Workshop on Scientific Applications of Grid Computing (SAG 2004) CY SEP 20-24, 2004 CL Beijing, PEOPLES R CHINA AB In data intensive sciences like High Energy Physics, large amounts of data are typically distributed and/or replicated to several sites. Although there exist various ways to store and access this data within a Grid environment, site security policies often prohibit end user access to remote sites. These limitations are typically overcome using a proxy service that requires limited network connections to and from remote sites. We present a novel proxy server for the xrootd data server that provides access to data stored in an object-oriented data store (typically in ROOT format). Our proxy service operates in a structured peer-to-peer environment and allows for fault tolerant and reliable access to remote data. C1 Stanford Univ, SLAC, Menlo Pk, CA 94025 USA. RP Hanushevsky, A (reprint author), Stanford Univ, SLAC, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. EM abla@slac.stanford.edu; Heinz@slac.stanford.edu NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-25810-8 J9 LECT NOTES COMPUT SC PY 2004 VL 3458 BP 38 EP 49 PG 12 WC Computer Science, Theory & Methods SC Computer Science GA BCO44 UT WOS:000230410900004 ER PT S AU Hanson, BD Stout, RB AF Hanson, BD Stout, RB BE Hanchar, JM StroesGascoyne, S Browning, L TI Reexamining the dissolution of spent fuel: A comparison of different methods for calculating rates SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID CORROSION AB Dissolution rates for spent fuel have typically been reported in terms of a rate normalized to the surface area of the specimen. Recent evidence has shown that neither the geometric surface area nor that measured with BET accurately predicts the effective surface area of spent fuel. Dissolution rates calculated from results obtained by flowthrough tests were reexamined comparing the cumulative releases and surface area normalized rates. While initial surface area is important for comparison of different rates, it appears that normalizing to the surface area introduces unnecessary uncertainty compared to using cumulative or fractional release rates. Discrepancies in past data analyses are mitigated using this alternative method. C1 Pacific NW Natl Lab, Radiochem Sci & Engn Grp, Richland, WA 99352 USA. RP Hanson, BD (reprint author), Pacific NW Natl Lab, Radiochem Sci & Engn Grp, Richland, WA 99352 USA. NR 12 TC 9 Z9 9 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 89 EP 94 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500013 ER PT S AU Jerden, JL Goldberg, MM Cunnane, JC Bauer, TH Wigeland, RA Nietert, RE AF Jerden, JL Goldberg, MM Cunnane, JC Bauer, TH Wigeland, RA Nietert, RE BE Hanchar, JM StroesGascoyne, S Browning, L TI Can spent nuclear fuel decay heat prevent radionuclide release? SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst AB Heat generated by radioactive decay of spent fuel represents a potentially important barrier to water accumulation on commercial spent nuclear fuel in breached waste packages. In the absence of water, fuel degradation and radionuclide release will be negligible. Thermal models for the proposed Yucca Mountain Repository suggest that, after a period of approximately 1000-4000 years (depending on loading and ventilation conditions), the repository drift walls may decline to sub-boiling temperatures, thus allowing humidity in the drift to increase. The question thus arises, is the thermal gradient between the fuel and the drift sufficient to prevent water accumulation in a humid drift environment throughout the regulatory period? The answer depends on the balance between processes that oppose water condensation onto the fuel (decay beat) and those that promote condensation such as the deliquescence of hygroscopic phases within the fuel. Our experimental results indicate that deliquescence could lead to the condensation of water onto spent fuel despite the thermal "self-drying" effect if the following criteria are met: (1) the fission product salt CsI is present in the fuel or in the fuel-cladding gap, (2) the relative humidity in the drift exceeds 80% while temperatures in the waste package are around 90degreesC. Previous work suggests that these criteria may be met for some fuel pins within the proposed Yucca Mountain Repository. However, experiments that account for the role of U(VI) alteration phases suggest that deliquescence may be a self-limiting process in the sense that deliquescent components (e.g. Cs, Ba, Sr) may be incorporated into nondeliquescent U(VI) phases that form from the corrosion of spent fuel. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Jerden, JL (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 101 EP 106 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500015 ER PT S AU Fortner, JA Kropf, AJ Finch, RJ Cunnane, JC AF Fortner, JA Kropf, AJ Finch, RJ Cunnane, JC BE Hanchar, JM StroesGascoyne, S Browning, L TI Technetium and molybdenum in oxide spent nuclear fuel: Impact on release estimates SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID CORROSION AB Technetium-99 ((99)Tc) is an important radionuclide in repository models owing to its relatively long half-life and the high aqueous solubility of compounds where it is in the heptavalent state. The vast majority of the (99)Tc inventory presently slated for disposal is contained in oxide commercial spent nuclear fuel (CSNF), where it is divided (along with its cohort, molybdenum) between exsolved, intermetallic "epsilon" particles and isolated, likely oxidized, atoms distributed in the uranium dioxide matrix. We present recent evidence from synchrotron x-ray fluorescence spectroscopy, electron microscopy, and fuel dissolution testing on the likely oxidation state, coordination environment, and physical disposition of technetium and molybdenum in CSNF. Effects of the relative proportioning of technetium and molybdenum among the metallic and oxidized states in CSNF, and their distribution in or near grain boundaries and gaps on release during CSNF corrosion testing are discussed. C1 Argonne Natl Lab, Chem Engn Div, Argonne, IL 60439 USA. RP Fortner, JA (reprint author), Argonne Natl Lab, Chem Engn Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM fortner@cmt.anl.gov RI Finch, Robert/D-9553-2013; ID, MRCAT/G-7586-2011 OI Finch, Robert/0000-0001-9342-5574; NR 14 TC 1 Z9 1 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 107 EP 112 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500016 ER PT S AU Hanson, BD Friese, JI Soderquist, CZ AF Hanson, BD Friese, JI Soderquist, CZ BE Hanchar, JM StroesGascoyne, S Browning, L TI Initial results from dissolution testing of spent fuel under acidic conditions SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst AB Flowthrough dissolution tests using solutions with pH in the range 2 to 7 have been conducted on a moderate burnup Light Water Reactor spent fuel. Such low pH conditions have been modeled as possibly occurring in a failed waste package at the proposed repository at Yucca Mountain. The release of total uranium, Tc-99, Sr-90, Cs-137, and Pu-239&240 were measured for up to 90% total reaction of the specimens. The reaction rates, determined both from the cumulative release and the release normalized to surface area, were found to decrease with increasing pH and with increasing extent of reaction. The implications to instantaneous release and long-term behavior in a geologic repository are discussed. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Hanson, BD (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 113 EP 118 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500017 ER PT S AU Friese, JI Douglas, M Buck, EC Clark, SB Hanson, BD AF Friese, JI Douglas, M Buck, EC Clark, SB Hanson, BD BE Hanchar, JM StroesGascoyne, S Browning, L TI Neptunium(V) incorporation/sorption with uranium(VI) alteration products SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID SPENT NUCLEAR-FUEL; YUCCA MOUNTAIN; MECHANISMS; CORROSION AB An initial uranium phase that has been observed to form during the corrosion of spent nuclear fuel is the uranium oxy-hydroxide metaschoepite. It has been proposed that neptunium(V) solubility can be limited by its association with this uranium phase. Metaschoepite has been synthesized in the presence of neptunium(V) over the pH range modeled in the proposed Yucca Mountain geologic repository. Uranium (VI) phases were synthesized by varying pH and neptunium concentrations. Results of neptunium association with the uranium alteration phases are presented and the relationship to dissolved neptunium concentrations discussed. C1 Pacific NW Natl Lab, Radiol Proc Lab, Richland, WA 99352 USA. RP Friese, JI (reprint author), Pacific NW Natl Lab, Radiol Proc Lab, Richland, WA 99352 USA. RI Buck, Edgar/D-4288-2009; Buck, Edgar/N-7820-2013; OI Buck, Edgar/0000-0001-5101-9084; Douglas, Matthew/0000-0001-9708-1780 NR 19 TC 3 Z9 3 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 127 EP 132 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500019 ER PT S AU Buck, EC Hanson, BD Friese, JI Douglas, M McNamara, BK AF Buck, EC Hanson, BD Friese, JI Douglas, M McNamara, BK BE Hanchar, JM StroesGascoyne, S Browning, L TI Evidence for neptunium incorporation into uranium (VI) phases SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID SPENT NUCLEAR-FUEL; CORROSION; 90-DEGREES-C; MECHANISMS; UO2 AB This paper examines the ability of electron energy-loss spectroscopy (EELS) combined with transmission electron microscopy (TEM) to detect both low concentrations of Np in a U matrix and to provide evidence for incorporation of Np in U(VI) phases. The case for U(VI) secondary minerals acting as solubility-controlling phases for Np in repository performance assessment models has not been fully established. Direct evidence for incorporation, rather than sorption, continues to be difficult to obtain. Detection of Np with TEM-EELS is hampered by the occurrence of a plural (multiple) scattering event from the more abundant U atoms (U-M-5 + U-O-4,(5)), that results in severe overlap on the Np-M-5 edge at similar to3665 eV. By examining the energy 'gap' between the Np-M-5 and Np-M-4 edges (184 eV), a method for observing Np independently of the plural scattering event has been established. Clear evidence of Np incorporation into synthetic studtite {(UO2)(O-2)(H2O)(2)](H2O)(2)} and uranophane {Ca(UO2)(2)(SiO3OH)(2)(H2O)(5)} has been found with TEM-EELS. The EELS technique continues to remain an important tool for examining the potential for transuranic behavior in nuclear waste materials. C1 Pacific NW Natl Lab, Environm Technol Div, Richland, WA 99352 USA. RP Buck, EC (reprint author), Pacific NW Natl Lab, Environm Technol Div, 902 Battelle Blvd, Richland, WA 99352 USA. RI Buck, Edgar/D-4288-2009; Buck, Edgar/N-7820-2013; OI Buck, Edgar/0000-0001-5101-9084; Douglas, Matthew/0000-0001-9708-1780 NR 15 TC 6 Z9 6 U1 0 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 133 EP 138 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500020 ER PT S AU McNamara, B Hanson, B Buck, E Soderquist, C AF McNamara, B Hanson, B Buck, E Soderquist, C BE Hanchar, JM StroesGascoyne, S Browning, L TI A radiochemical analyses of metastudtite and leachates from spent fuel SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID SOLUBILITY; STUDTITE; PEROXIDE AB We have characterized considerable amounts of the two known uranyl peroxide phases that formed under static immersion conditions on commercial spent nuclear fuel (CSNF) samples. Milligrams of corroded fuel aggregates were observed at the air-water interface in each sample. The bulk fuel and the interfacial solids were examined by SEM, EDX, and XRD and were found to contain studtite and metastudtite, respectively. The reason for the partitioning of the two phases is not clear at this time. The unique occurrence of the floating phase prompted a radiochemical analysis of these solids. The analysis indicated that Sr-90, Cs-137, Tc-99, and to a lesser extent of Pu-239,Pu-239 and Np-237, had partitioned with the air-water interface aggregates. The concentration of Am-241 in the interfacial solids was two orders of magnitude lower than the inventory in the fuel prior to contact with water. The radiochemical analyses of two fuel leachate samples are compared to reported leaching data of a similar fuel which did not result in the formation of studtite. C1 Pacific NW Natl Lab, Radiochem Proc Lab, Richland, WA 99352 USA. RP McNamara, B (reprint author), Pacific NW Natl Lab, Radiochem Proc Lab, 902 Battelle Blvd, Richland, WA 99352 USA. RI Buck, Edgar/D-4288-2009; Buck, Edgar/N-7820-2013 OI Buck, Edgar/0000-0001-5101-9084 NR 15 TC 5 Z9 5 U1 0 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 139 EP 144 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500021 ER PT S AU Scheele, RD Hanson, BD Cumblidge, SE Jenson, ED Kozelisky, AE Sell, RL MacFarlan, PJ Snow, LA AF Scheele, RD Hanson, BD Cumblidge, SE Jenson, ED Kozelisky, AE Sell, RL MacFarlan, PJ Snow, LA BE Hanchar, JM StroesGascoyne, S Browning, L TI Effect of gadolinium doping on the air oxidation of uranium dioxide SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID FISSION-PRODUCTS; UO2 AB Researchers at the Pacific Northwest National Laboratory (PNNL) investigated the effects of gadolinium oxide concentration on the air oxidization of gadolinium oxide-doped uranium dioxide using thermogravimetry and differential scanning calorimetry to determine if such doping could improve uranium dioxide's stability as a nuclear fuel during potential accident scenarios in a nuclear reactor or during long-term disposal. We undertook this study to determine whether the resistance of the uranium dioxide to oxidation to the orthorhombic U3O8 with its attendant crystal expansion could be prevented by addition of gadolinium oxide. Our studies found that gadolinium has little effect on the thermal initiation of the first step of the reported two-step air oxidation of UO2; however, increasing gadolinium oxide content does stabilize the initial tetragonal or cubic product allowing significant oxidation before the second expansive Step to U3O8 begins. C1 Pacific NW Natl Lab, Environm Technol Directorate, Richland, WA 99352 USA. RP Scheele, RD (reprint author), Pacific NW Natl Lab, Environm Technol Directorate, Richland, WA 99352 USA. NR 8 TC 1 Z9 1 U1 1 U2 3 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 211 EP 216 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500031 ER PT S AU Ebert, WL AF Ebert, WL BE Hanchar, JM StroesGascoyne, S Browning, L TI Application of the TSPA glass degradation model to non-conforming waste forms SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst AB An approach is presented for determining if the models used to calculate the release of radionuclides from defense high-level radioactive waste (HLW) glass for total system performance assessment (TSPA) calculations can be used to account for the release of radionuclides from waste forms other than standard borosilicate glasses. The fractional release rates of radionuclides due to waste form degradation, the available surface area, and the radionuclide inventory in an alternative waste form can be compared with the corresponding models used in TSPA for HLW glasses to determine if those models adequately represent the waste form. This approach is demonstrated for the ceramic and metallic waste forms developed for electrometallurgically treated spent sodium-bonded nuclear fuel. Depending on the waste form, comparisons made with aspects of the HLW glass model may be based on similarities in degradation mechanisms or purely empirical. C1 Argonne Natl Lab, Div Chem Engn, Argonne, IL 60439 USA. RP Ebert, WL (reprint author), Argonne Natl Lab, Div Chem Engn, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 301 EP 308 PG 8 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500045 ER PT S AU Mattigod, SV Whyatt, GA Serne, JR Wood, MI AF Mattigod, SV Whyatt, GA Serne, JR Wood, MI BE Hanchar, JM StroesGascoyne, S Browning, L TI Diffusion of iodine and Technetium-99 through waste encasement concrete and unsaturated soil fill material SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst AB An assessment of long-term performance of low level waste-enclosing cement grouts requires diffusivity data for radionuclide species such as, I-129 and Tc-99. The diffusivity of radionuclides in soil and concrete media was collected by conducting soil-soil and concrete-soil half-cell experiments. The soil diffusivity coefficients for iodide were 7.03 x 10(-8) cm(2)/s and 2.42 x 10(-7) cm(2)/s for soils at 4% and 7% moisture contents, respectively. Iodide diffusivity in soil is a function of moisture content and is about an order of magnitude slower at lower moisture content. The soil diffiisivity coefficients for Tc-99 were 5.89+/-0.80 x 10(-8) cm(2)/s (4% moisture content) and 2.04+/-0.57 x 10(-7) cm(2)/s (7% moisture content), respectively. The soil diffusivity of iodide and Tc-99; were similar in magnitude at both water contents, indicating that these ions have similar diffusion mechanisms in unsaturated coarse-textured Hanford soil. The diffusivity of iodide in concrete ranged from 2.07 x 10(-14) cm(2)/s (4% soil moisture content) to 1.31 X 10(-12) cm(2)/s (7% soil moisture content), indicating that under unsaturated soil moisture conditions, iodide diffusivity is highly sensitive to changing soil moisture conditions. Depending on the soil moisture content, the diffusivity of Tc-99 in concrete ranged from 4.54 x 10(-13) cm(2)/s to 8.02 x 10(-12) cm(2)/s. At 4% soil moisture content, iodide diffused about 20 times more slowly than Tc-99, and at 7% soil moisture content, iodide in concrete diffused about 6 times slower than Tc-99. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Mattigod, SV (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 14 TC 0 Z9 0 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 391 EP 398 PG 8 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500059 ER PT S AU Hu, QH Smith, DK AF Hu, QH Smith, DK BE Hanchar, JM StroesGascoyne, S Browning, L TI Field-scale migration of Tc-99 and I-129 at the Nevada Test Site SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst AB The groundwater at the Nevada Test Site (NTS) contains many long-lived radionuclides, including Tc-99 (technetium) and I-129 (iodine), as a result of 828 underground nuclear weapons tests conducted between 1951 and 1992. We synthesized a body of data collected on the distribution of Tc-99 and I-129 in groundwater to assess their migration at NTS, at field scales over distances of hundreds of meters and for durations up to forty years and under hydrogeologic conditions very similar to the proposed geological repository at Yucca Mountain. The results of our study show that Tc does not necessarily exist as a mobile and conservative species TcO4-, as has been commonly assumed. This conclusion is corroborated by recent in situ redox potential measurements, which show that groundwaters at multiple locations of the NTS are not oxidizing, and mobility of reduced Tc species (TcO(2)(.)nH(2)O) is greatly decreased. Speciation of iodine and its associated reactivity is also complex in the groundwater at the NTS, and its effect on the mobility of iodine should be the subject of future studies. C1 Lawrence Livermore Natl Lab, Chem Biol & Nucl Sci Div, Livermore, CA 94550 USA. RP Hu, QH (reprint author), Lawrence Livermore Natl Lab, Chem Biol & Nucl Sci Div, 7000 E Ave,MS L-231, Livermore, CA 94550 USA. NR 9 TC 2 Z9 2 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 399 EP 404 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500060 ER PT S AU Sutton, M Alai, M Carroll, S AF Sutton, M Alai, M Carroll, S BE Hanchar, JM StroesGascoyne, S Browning, L TI Evaporative evolution of carbonate-rich brines from synthetic Topopah Spring Tuff pore water, Yucca Mountain, NV SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID SYSTEM; MODEL AB The evaporation of a range of synthetic pore water solutions representative of the potential highlevel-nuclear-waste repository at Yucca Mountain, NV is being investigated. The motivation of this work is to understand and predict the range of brine compositions that may contact the waste containers from evaporation of pore waters, because these brines could form coffosive thin films on the containers and impact their long-term integrity. A relatively complex synthetic Topopah Spring Tuff pore water was progressively concentrated by evaporation in a closed vessel, heated to 95degreesC in a series of sequential experiments. Periodic samples of the evaporating solution were taken to determine the evolving water chemistry. According to chemical divide theory at 25degreesC and 95degreesC our starting solution should evolve towards a high pH carbonate brine. Results at 95degreesC show that this solution evolves towards a complex brine that contains about 99 mol% Na+ for the cations, and 71 mol% Cl-, 18 mol% SigmaCO(2)(aq), 9 mol% SO42- for the anions. Initial modeling of the evaporating solution indicates precipitation of aragonite, halite, silica, sulfate and fluoride phases. The experiments have been used to benchmark the use of the EQ3/6 geochemical code in predicting the evolution of carbonate-rich brines during evaporation. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sutton, M (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 497 EP 502 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500076 ER PT S AU Zhang, ZC Rao, LF Rai, DP Clark, SB AF Zhang, ZC Rao, LF Rai, DP Clark, SB BE Hanchar, JM StroesGascoyne, S Browning, L TI Characterization of chromium(III) hydroxide solids and their oxidation by hydrogen peroxide SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst AB Chromium is of great concern in the vitrification of high-level nuclear waste sludges because it forms separate crystallites in the molten glass. Inadequate removal of chromium from sludges could result in the production of an unacceptably large volume of HLW glass. Alkaline oxidative leaching is considered one of the pretreatment strategies to remove chromium before the vitrification. In this study, Cr(III) hydroxide solids were prepared under different conditions and characterized by EXAFS and IR. The rate of oxidation of the solids by hydrogen peroxide in alkaline solutions was studied by UV absorption spectroscopy. EXAFS and IR experiments indicate that the degree of oligomerization in the Cr(III) hydroxide solids increases with the increase in the concentration of NaOH in solution, the aging temperature and the aging time. The rate of oxidation of the solids follows the same order previously observed for Cr(III) oligomers in solution, i.e., species with higher degree of oligornerization are oxidized more slowly. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Rao, LF (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 10 TC 0 Z9 0 U1 1 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 589 EP 594 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500088 ER PT S AU Tranter, TJ Vereshchagina, TA Anshits, AG Fomenko, E Aloy, AS Sapozhnikova, NV AF Tranter, TJ Vereshchagina, TA Anshits, AG Fomenko, E Aloy, AS Sapozhnikova, NV BE Hanchar, JM StroesGascoyne, S Browning, L TI Separation of Cs-137 from acidic nuclear waste simulant via an engineered inorganic ion exchanger SO SCIENTIFIC BASIS FOR NUCLEAR WASTE MANAGEMENT XXVIII SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT 28th Symposium on the Scientific Basis for Nuclear Waste Management held at the 2004 MRS Spring Meeting CY APR 13-16, 2004 CL San Francisco, CA SP Mat Res Soc, SW Res Inst ID SORBENTS; CESIUM AB An engineered ion exchange material has been prepared for the specific purpose of removing radioactive cesium from acidic waste. Separating the fission product Cs-137 from the bulk of the nuclear waste stream is often advantageous because, after typical cooling times, this isotope is usually the primary source of gamma radiation dose. The engineered ion exchanger was prepared using ammonium molybdophosphate impregnated into hollow glass crystalline microspheres. The microspheres or cenospheres, are refractory compounds of silica and alumina that are derived from the fly ash produced in coal combustion. This paper describes equilibrium experiments that were conducted with the engineered ion exchanger and a simulated acidic waste solution. These tests indicate that the new material has a high capacity and selectivity for cesium in these matrices. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Tranter, TJ (reprint author), Idaho Natl Engn & Environm Lab, POB 1625, Idaho Falls, ID 83415 USA. RI Vereshchagina, Tatiana/A-5764-2014; Fomenko, Elena/D-5106-2013; Anshits, Alexander/E-8823-2014 OI Vereshchagina, Tatiana/0000-0003-4538-8902; Fomenko, Elena/0000-0003-0929-807X; Anshits, Alexander/0000-0002-5259-0319 NR 11 TC 0 Z9 1 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-774-1 J9 MATER RES SOC SYMP P PY 2004 VL 824 BP 601 EP 606 PG 6 WC Energy & Fuels; Materials Science, Ceramics; Nuclear Science & Technology SC Energy & Fuels; Materials Science; Nuclear Science & Technology GA BBB44 UT WOS:000224543500090 ER PT B AU Groom, D AF Groom, D BE Amico, P Beletic, JW Beletic, JE TI Cosmic rays and other nonsense in astronomical CCD imagers SO SCIENTIFIC DETECTORS FOR ASTRONOMY: THE BEGINNING OF A NEW ERA SE ASTROPHYSICS AND SPACE SCIENCE LIBRARY LA English DT Proceedings Paper CT Scientific Detectors for Astronomy Workshop (SDW2002) CY JUN, 2002 CL Waimea, HI DE Charge-Coupled Device (CCD); cosmic rays; high resistivity; fully depleted; back illuminated; Compton scattering; gamma ray AB Cosmic-ray muons make recognizable straight tracks in the new-generation CCD's with thick sensitive regions. Wandering tracks ("worms"), which we identify with multiply-scattered low-energy electrons, are readily recognized as different from the muon tracks. These appear to be mostly recognized as Compton-scattered gamma rays, although worms are also produced directly by beta emitters in dewar windows and field lenses. The gamma rays are mostly byproducts of K-40 decay and the U and Th decay chains. Trace amounts of these elements are nearly always present in concrete and other materials. The direct betas can be eliminated and the Compton recoils can be reduced significantly by the judicious choice of materials and shielding. The cosmic-ray muon rate is irreducible. Our conclusions are supported by tests at the Lawrence Berkeley National Laboratory low-level counting facilities in Berkeley and 180 in underground at Oroville, California. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Groom, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-1788-X J9 ASTROPHYS SPACE SC L PY 2004 VL 300 BP 81 EP 94 PG 14 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BAN06 UT WOS:000222918100009 ER PT B AU Holland, S AF Holland, S BE Amico, P Beletic, JW Beletic, JE TI An overview of CCD development at Lawrence Berkeley National Laboratory SO SCIENTIFIC DETECTORS FOR ASTRONOMY: THE BEGINNING OF A NEW ERA SE ASTROPHYSICS AND SPACE SCIENCE LIBRARY LA English DT Proceedings Paper CT Scientific Detectors for Astronomy Workshop (SDW2002) CY JUN, 2002 CL Waimea, HI DE Charge-Coupled Device (CCD); fully depleted; back illuminated; high-resistivity silicon AB Fully depleted, back-illuminated charge-coupled devices fabricated at Lawrence Berkeley National Laboratory on high-resistivity silicon are described Device operation and technology are discussed, as well as the results on telescopes and future plans. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Holland, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-1788-X J9 ASTROPHYS SPACE SC L PY 2004 VL 300 BP 95 EP 102 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BAN06 UT WOS:000222918100010 ER PT S AU Graham, GA Kearsley, AT Butterworth, AL Bland, PA Burchell, MJ McPhail, DS Chater, R Grady, MM Wright, IP AF Graham, GA Kearsley, AT Butterworth, AL Bland, PA Burchell, MJ McPhail, DS Chater, R Grady, MM Wright, IP BE Lebreton, JP Agee, CB Stabekis, PD Bernhardt, P Ganguli, GI TI Extraction and microanalysis of cosmic dust captured during sample return missions: laboratory simulations SO SCIENTIFIC EXPLORATION, PLANETARY PROTECTION, ACTIVE EXPERIMENTS AND DUSTY PLASMAS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE cosmic dust; sample return missions; extraction and microanalysis; laboratory simulations ID HYPERVELOCITY IMPACT; PARTICLES; AEROGEL AB Particles of cometary and asteroidal origin collected at source using dedicated capture cell technologies will be returned to Earth within the next 8 years. Furthermore, coincidental capture of interplanetary dust particles will occur on the exposed surfaces of the Genesis spacecraft. Laboratory simulations using both light-gas-gun and Van de Graaff accelerators have impacted dust analogues at velocities ranging from 5 km s(-1) to ca. 72 km s(-1) into comparable silicon and aerogel targets. Analysis of the impacts on silicon has shown complete spallation of impact residues for silicate projectiles of 38-53 mum in diameter, however craters formed by 1 mum iron projectiles show that near-intact residues can be preserved. An olivine grain embedded in aerogel has been characterized in situ using Raman micro-spectroscopy. Monte Carlo simulations and laboratory experiments have shown that analytical scanning electron microscopy can also be used to characterize embedded grains. Development of a novel particle extraction methodology using a 266 nm UV laser micro-dissection system has resulted in the recovery of an olivine grain. The extracted particle was then "cleaned up" using focused ion beam (FIB) milling to remove excess aerogel that was fused on the grain surface. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Nat Hist Museum, Dept Mineral, London SW7 5BD, England. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ London Imperial Coll Sci Technol & Med, Dept Earth Sci & Engn, London SW7 2BP, England. Univ Kent, Ctr Astrophys & Planetary Sci, Canterbury CT2 7NR, Kent, England. Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2BP, England. RP Graham, GA (reprint author), Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, POB 808,L413, Livermore, CA 94550 USA. EM graham42@llnl.gov OI Grady, Monica/0000-0002-4055-533X; Burchell, Mark/0000-0002-2680-8943 NR 20 TC 9 Z9 9 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2004 VL 34 IS 11 BP 2292 EP 2298 DI 10.1016/j.asr.2003.07.066 PG 7 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BBN86 UT WOS:000226379100010 ER PT J AU Hou, PY Zhang, XF Cannon, RM AF Hou, PY Zhang, XF Cannon, RM TI Impurity distribution in Al(2)O(3) formed on an FeCrAl alloy SO SCRIPTA MATERIALIA LA English DT Article DE oxidation; iron alloys; alumina; analytical electron microscopy; AES ID HIGH-TEMPERATURE OXIDATION; FE-CR-AL; GROWTH MECHANISMS; GRAIN-BOUNDARIES; ALUMINA SCALES; CREEP; SEGREGATION; ALPHA-AL2O3; BEHAVIOR; YTTRIUM AB Analytical electron microscopy and Auger spectroscopy were used to study the amount and distribution of Fe, Cr and S impurities in the Al(2)O(3) scale grown on an FeCrAl alloy. Segregations of Fe on grain boundaries and S on internal void surfaces were found, and a mechanism of intragranular void formation in Al(2)O(3) is proposed. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Lawrence Berkeley Natl Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Hou, PY (reprint author), Lawrence Berkeley Natl Lab, Div Sci Mat, MS 62-203,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM pyhou@lbl.gov NR 25 TC 29 Z9 31 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN PY 2004 VL 50 IS 1 BP 45 EP 49 DI 10.1016/j.scriptamat.2003.09.044 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 737BD UT WOS:000186207800009 ER PT S AU Koller, J Li, H AF Koller, J Li, H BE Holt, SS Deming, D TI Vorticity generation in protoplanetary disks SO SEARCH FOR OTHER WORLDS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 14th Annual Astrophysics Conference CY OCT 13-14, 2003 CL College Pk, MD SP NASA, Goddard Space Flight Ctr, Univ Maryland ID ACCRETION; MIGRATION; NEBULA AB Global two-dimensional inviscid protoplanetary disk simulation show the generation of vorticity in the co-orbital region of the planet. Emanating shock waves from the planet lead to nonconservation of vorticity along particle paths. As the system evolves, the potential vorticity (PV or vortensity) profiles eventually develop extrema which renders the disk unstable and vortices emerge. We discuss how these changes occur along particle paths. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Koller, J (reprint author), Los Alamos Natl Lab, Div Appl Phys, X-1,MS P225, Los Alamos, NM 87545 USA. NR 9 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0190-X J9 AIP CONF PROC PY 2004 VL 713 BP 63 EP 66 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAM87 UT WOS:000222875000011 ER PT S AU Zhang, Y Mascarenhas, A AF Zhang, Y Mascarenhas, A BE Norman, AG Goldman, RS Noetzel, R Stringfellow, GB TI Effects due to and derived from spontaneous ordering in IH-V semiconductor alloys SO SELF-ORGANIZED PROCESSES IN SEMICONDUCTOR HETEROEPITAXY SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT Symposium on Self-Organized Processes in Semiconductor Epitaxy held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc ID PHOTONIC CRYSTALS; NEGATIVE REFRACTION; INDEX AB Two interesting and important aspects of spontaneous CuPt ordering in III-V semiconductor alloys, which have only been investigated recently, are reviewed in this paper. ne first aspect addresses the statistical effects that should be considered as the most unique consequence of the phenomenon of ordering, more specifically, how ordering affects the alloy fluctuations and hence the physical properties of the alloy. The second aspect tackles some intriguing properties of the domain twins of two CuPt ordered variants, specifically, considering the transmission of a ballistic electron beam through such a domain twin and its analogy to a highly interesting phenomenon, negative refraction, for light. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM yzhang@nrel.gov NR 24 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOC PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-732-6 J9 MATER RES SOC SYMP P PY 2004 VL 794 BP 279 EP 290 PG 12 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BAH11 UT WOS:000222180100037 ER PT S AU Batyrev, IG Norman, AG Zhang, SB Wei, SH AF Batyrev, IG Norman, AG Zhang, SB Wei, SH BE Norman, AG Goldman, RS Noetzel, R Stringfellow, GB TI Quadruple-period ordering in MBE GaAsSb alloys SO SELF-ORGANIZED PROCESSES IN SEMICONDUCTOR HETEROEPITAXY SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT Symposium on Self-Organized Processes in Semiconductor Epitaxy held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc ID SURFACE RECONSTRUCTION; SEGREGATION; GA0.5IN0.5P; GAAS(001); LAYERS; GAINP AB Experimental and theoretical studies are reported for a quadruple period ordering found in GaAsSb alloy layers grown by molecular beam epitaxy at high growth temperatures. We propose a growth model that accounts for the observed three-dimensional (3D) ordered structure. It is shown that the already-ordered material in the previously grown layer affects the reconstruction of the growth front with respect to the underlying alloy template resulting in the correct stacking of the individual 2D ordered layers into the observed 3D ordered structure. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Batyrev, IG (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Norman, Andrew/F-1859-2010; Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Norman, Andrew/0000-0001-6368-521X; Zhang, Shengbai/0000-0003-0833-5860 NR 30 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOC PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-732-6 J9 MATER RES SOC SYMP P PY 2004 VL 794 BP 297 EP 307 PG 11 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA BAH11 UT WOS:000222180100039 ER PT J AU Bychkov, E Tveryanovich, Y Vlasov, Y AF Bychkov, E Tveryanovich, Y Vlasov, Y TI Ion conductivity and sensors SO SEMICONDUCTING CHALCOGENIDE GLASS III: APPLICATIONS OF CHALCOGENIDE GLASSES SE SEMICONDUCTORS AND SEMIMETALS LA English DT Article ID CHALCOGENIDE GLASS ELECTRODES; BULK MEMBRANE-TRANSPORT; PULSED-LASER DEPOSITION; SULFIDE BASED GLASSES; SHORT-RANGE ORDER; X-RAY-SCATTERING; CHEMICAL SENSORS; TRACER DIFFUSION; ELECTRICAL-CONDUCTIVITY; NEUTRON-DIFFRACTION C1 Argonne Natl Lab, Argonne, IL 60439 USA. St Petersburg State Univ, St Petersburg 199034, Russia. RP Bychkov, E (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Tveryanovich, Yury/M-9054-2013 OI Tveryanovich, Yury/0000-0003-4343-9817 NR 137 TC 5 Z9 5 U1 1 U2 1 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0080-8784 J9 SEMICONDUCT SEMIMET PY 2004 VL 80 BP 103 EP 168 DI 10.1016/S0080-8784(04)80027-9 PG 66 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BCB27 UT WOS:000228485900003 ER PT S AU Wieczorek, S Chow, WW AF Wieczorek, S Chow, WW BE Lenstra, D Morthier, G Erneux, T Pessa, M TI Dynamics of multimode coupled lasers SO SEMICONDUCTOR LASERS AND LASER DYNAMICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Semiconductor Lasers and Laser Dynamics CY APR 27-30, 2004 CL Strasbourg, FRANCE SP SPIE DE coupled lasers; multimode lasers; composite-cavity modes; bifurcation diagram ID SEMICLASSICAL THEORY; CHAOS AB The paper is concerned with a theoretical study of synchronization between two end-to-end coupled lasers. Lasers are treated within the framework of a special multimode theory, valid for arbitrary coupling between lasers, where the laser field is decomposed in terms of the composite-cavity modes of the entire coupled-laser system. Bifurcation continuation techniques are used to systematically investigate the resulting equations under class-A, and further under class-B approximation. We discovered that the mechanism leading to laser synchronization changes from strong composite-cavity mode competition in class-A regime to frequency locking of composite-cavity modes in class-B regime. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Wieczorek, S (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5375-7 J9 P SOC PHOTO-OPT INS PY 2004 VL 5452 BP 71 EP 81 DI 10.1117/12.544933 PG 11 WC Optics SC Optics GA BAZ49 UT WOS:000224316200008 ER PT J AU Drichko, IL D'yakonov, AM Smirnov, IY Gal'perin, YM Preobrazhenskii, VV Toropov, AI AF Drichko, IL D'yakonov, AM Smirnov, IY Gal'perin, YM Preobrazhenskii, VV Toropov, AI TI Role of Si-doped Al0.3Ga0.7As layers in the high-frequency conductivity of GaAs/Al0.3Ga0.7As heterostructures under conditions of the quantum hall effect SO SEMICONDUCTORS LA English DT Article ID 2-DIMENSIONAL ELECTRON-GAS; LOCALIZATION LENGTH; EFFECT REGIME; SEMICONDUCTORS; TRANSPORT; MOBILITY AB The complex high-frequency conductivity of GaAs/Al0.3Ga0.7As heterostructures that are delta-doped and modulation-doped with silicon was investigated by acoustic methods under conditions of the integer quantum Hall effect. Both the real (sigma(1)) and imaginary (sigma(2)) parts of the complex conductivity sigma(omega, H)=sigma(i)-isigma(2) were determined from the dependences of the absorption and velocity of surface acoustic waves on magnetic field. It is shown that, in the heterostructures with electron density n(s)=(1.3-7)x10(11) cm(-2) and mobility mu=(1-2)x10(5) cm(2)/(V s), the high-frequency conductivity near the centers of the Hall plateau is due to electron hopping between localized states. It is established that, with filling numbers 2 and 4, the conductivity of the Al0.3Ga0.7As:Si layer efficiently shunts the high-frequency hopping conductivity of the two-dimensional interface layer. A method of separating the contributions of the interface and Al0.3Ga0.7As:Si layers to the hopping conductivity sigma(omega, H) is developed. The localization length of electrons in the interface layer is determined on the basis of the nearest neighbor hopping model. It is shown that, near the centers of the Hall plateau, both sigma(omega, H) and n(s) depend on the cooling rate of a GaAs/Al0.3Ga0.7As sample. As a result, the sample "remembers" the cooling conditions. Infrared light and static strain also change both sigma(omega, H) and n(s). We attribute this behavior to the presence of two-electron defects (so-called DX- centers) in the Al0.3Ga0.7As:Si layer. (C) 2004 MAIK "Nauka/Interperiodica". C1 Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. Argonne Natl Lab, Argonne, IL 60439 USA. Russian Acad Sci, Inst Semicond Phys, Siberian Div, Novosibirsk 630090, Russia. RP Drichko, IL (reprint author), Russian Acad Sci, AF Ioffe Physicotech Inst, Politekhnicheskaya Ul 26, St Petersburg 194021, Russia. EM Irina.L.Drichko@mail.ioffe.ru RI Smirnov, Ivan/E-4685-2014 NR 20 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1063-7826 J9 SEMICONDUCTORS+ JI Semiconductors PY 2004 VL 38 IS 6 BP 702 EP 711 DI 10.1134/1.1766376 PG 10 WC Physics, Condensed Matter SC Physics GA 828CZ UT WOS:000221951800015 ER PT J AU McConnell, R AF McConnell, R TI Next-generation technologies in the USA SO SEMICONDUCTORS LA English DT Article; Proceedings Paper CT Symposium on the Efficient Use of Solar Radiation in Photovoltaic Power Engineering CY NOV 03-04, 2003 CL St Petersburg, RUSSIA ID SOLAR-CELLS AB This presentation describes the highlights of exploratory research into next-generation photovoltaic (PV) technologies funded by the United States Department of Energy (DOE) for the purpose of finding disruptive or "leap frog" technologies that have a chance of leaping ahead, both in terms of vastly higher conversion efficiencies and greater penetration of the PV energy marketplace. Next-generation PV technologies are defined as those not in production or only in limited production because of the need for additional long-term research, development, innovation, and commercialization. Since 1999, DOE and the National Renewable Energy Laboratory have funded 33 universities and companies to explore these concepts, with a total annual budget of about $2 million per year. (C) 2004 MAIK "Nauka / Interperiodica". C1 Natl Renewable Energy Lab, Natl Ctr Photovoltaics, Golden, CO 80401 USA. RP McConnell, R (reprint author), Natl Renewable Energy Lab, Natl Ctr Photovoltaics, Golden, CO 80401 USA. EM robert_mcconnell@nrel.gov NR 13 TC 3 Z9 3 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1063-7826 J9 SEMICONDUCTORS+ JI Semiconductors PY 2004 VL 38 IS 8 BP 931 EP 935 DI 10.1134/1.1787114 PG 5 WC Physics, Condensed Matter SC Physics GA 845VQ UT WOS:000223273800006 ER PT J AU Perelson, AS Ribeiro, RM AF Perelson, AS Ribeiro, RM TI Hepatitis B virus kinetics and mathematical modeling SO SEMINARS IN LIVER DISEASE LA English DT Article; Proceedings Paper CT Scientific and Clinical Expert Panel Meeting on HBV Viral Kinetics and Clinical Management CY OCT 18, 2003 CL Chicago, IL DE hepatitis B virus; modeling; viral kinetics ID DYNAMICS IN-VIVO; VIRAL DYNAMICS; INFECTION; THERAPY; LAMIVUDINE; HIV-1; CLEARANCE; FAMCICLOVIR; LYMPHOCYTES; INTERFERON AB In this article, we review modeling and interpretation of kinetics data obtained from patients with chronic hepatitis B virus infection that has been treated with lamivudine, adefovir dipivoxil, and lamivudine plus famciclovir combination therapy. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Oxford, Dept Zool, Oxford OX1 3PS, England. Los Alamos Natl Lab, Los Alamos, NM USA. RP Perelson, AS (reprint author), Los Alamos Natl Lab, MS K710, Los Alamos, NM 87545 USA. EM asp@lanl.gov FU NCRR NIH HHS [RR06555] NR 19 TC 14 Z9 17 U1 0 U2 1 PU THIEME MEDICAL PUBL INC PI NEW YORK PA 333 SEVENTH AVE, NEW YORK, NY 10001 USA SN 0272-8087 J9 SEMIN LIVER DIS JI Semin. Liver Dis. PY 2004 VL 24 SU 1 BP 11 EP 16 DI 10.1055/s-2004-828673 PG 6 WC Gastroenterology & Hepatology SC Gastroenterology & Hepatology GA 829XD UT WOS:000222083800003 PM 15192796 ER PT J AU Tarver, EE AF Tarver, EE TI External second gate, Fourier Transform ion mobility spectrometry: Parametric optimization for detection of weapons of mass destruction SO SENSORS LA English DT Article DE ion mobility spectrometry; Fourier Transform ion mobility spectrometry; external second gate; Explosive samples AB Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and robust techniques for the detection of narcotics, explosives and chemical warfare agents. IMS is widely used in forensic, military and security applications. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention (CWC) treaty verification as well as humanitarian de-mining efforts have mandated that equal importance be placed on the time required to obtain results as well as the quality of the analytical data. [1] In this regard IMS is virtually unrivaled when both speed of response and sensitivity have to be considered. [2] The problem with conventional (signal averaging) IMS systems is the fixed duty cycle of the entrance gate that restricts to less than 1%, the number of available ions contributing to the measured signal. Furthermore, the signal averaging process incorporates scan-to-scan variations that degrade the spectral resolution contributing to misidentifications and false positives. With external second gate, Fourier Transform ion mobility spectrometry (FT-IMS) the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters (scan time and sampling rate) to increase the spectral resolution to reduce false alarms and improve the sensitivity for early warning and contamination avoidance. In addition, with FT-IMS the entrance gate operates with a 50% duty cycle and so affords a seven-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system. C1 Sandia Natl Labs, Analyt Mat Sci Dept, Livermore, CA 94551 USA. RP Tarver, EE (reprint author), Sandia Natl Labs, Analyt Mat Sci Dept, POB 969,Mail Stop 9403, Livermore, CA 94551 USA. EM eetarve@sandia.gov NR 8 TC 21 Z9 22 U1 0 U2 10 PU MOLECULAR DIVERSITY PRESERVATION INTERNATIONAL PI BASEL PA MATTHAEUSSTRASSE 11, CH-4057 BASEL, SWITZERLAND SN 1424-8220 J9 SENSORS-BASEL JI Sensors PD JAN-MAR PY 2004 VL 4 IS 1-3 BP 1 EP 13 DI 10.3390/s40100001 PG 13 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 807KF UT WOS:000220499700001 ER PT S AU Oluseyi, HM Bercovitz, JH Karcher, A Hernikl, CD Miller, T Uslenghi, M Roe, N Bebek, C Holland, S Levi, M AF Oluseyi, HM Bercovitz, JH Karcher, A Hernikl, CD Miller, T Uslenghi, M Roe, N Bebek, C Holland, S Levi, M BE Blouke, MM Sampat, N Motta, RJ TI LBNL 4-side buttable CCD package development SO SENSORS AND CAMERA SYSTEMS FOR SCIENTIFIC, INDUSTRIAL, AND DIGITAL PHOTOGRAPHY APPLICATIONS V SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Camera Systems for Scientific, Industrial, and Digital Photography Applications V CY JAN 19-21, 2004 CL San Jose, CA DE CCD; astronomical imaging; focal plane detectors; Lawrence Berkeley National Laboratory AB We have developed a precision, 4-side buttable CCD package for 2k x 2k and 2k x 4k format devices with minimal mechanical stress on the CCD, excellent thermal properties, reliable electrical connectivity, and shim-free mounting. We report on the package design, assembly and quality assurance procedures, measurements of flatness excursions when cooled from room temperature to 140 K, package performance and plans for future development. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Oluseyi, HM (reprint author), Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Holland, Stephen/H-7890-2013; OI Uslenghi, Michela/0000-0002-7585-8605 NR 13 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5204-1 J9 P SOC PHOTO-OPT INS PY 2004 VL 5301 BP 87 EP 98 DI 10.1117/12.531954 PG 12 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BAP45 UT WOS:000223125100011 ER PT S AU Harper, WW Strasburg, JD AF Harper, WW Strasburg, JD BE Carapezza, EM TI Remote chemical sensing with quantum cascade lasers SO SENSORS, AND COMMAND, CONTROL, COMMUNICATIONS, AND INTELLIGENCE(C31) TECHNOLOGIES FOR HOMELAND SECURITY AND HOMELAND DEFENSE III, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Command, Control, Communications and Intelligence (C31) Technologies for Homeland Security and Homeland Defense III CY APR 12-16, 2004 CL Orlando, FL SP SPIE DE remote sensing; lasers; lidar; chemical detection; quantum cascade laser ID MODULATION AB A trailer based sensor system has been developed for remote chemical sensing applications. The sensor uses quantum cascade lasers (QCL) that operate in the long wave infrared. The QCL is operated continuous wave, and its wavelength is both ramped over a molecular absorption feature and frequency modulated. Lock-in techniques are used to recover weak laser return signals. Field experiments have monitored ambient water vapor and small quantities of nitrous oxide, tetrafluoroethane (R134a), and hydrogen sulfide released as atmospheric plumes. Round trip path lengths up to 10 km were obtained using a retroreflector. Atmospheric turbulence was found to be the dominating noise source. It causes intensity fluctuations in the received power, which can significantly degrade the sensor performance. Unique properties associated with QCLs enabled single beam normalization techniques to be implemented thus reducing the impact that turbulence has on experimental signal to noise. Weighted data averaging was additionally used to increase the signal to noise of data traces. Absorbance sensitivities as low as similar to1X10(-4) could be achieved with 5 seconds of data averaging, even under high turbulence conditions. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Harper, WW (reprint author), Pacific NW Natl Lab, MS K5-25,POB 999, Richland, WA 99352 USA. NR 9 TC 2 Z9 2 U1 3 U2 6 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5326-9 J9 P SOC PHOTO-OPT INS PY 2004 VL 5403 BP 378 EP 386 DI 10.1117/12.541699 PN 1-2 PG 9 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Optics; Physics, Applied; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Physics; Imaging Science & Photographic Technology GA BAZ63 UT WOS:000224321700041 ER PT S AU Tarver, EE AF Tarver, EE BE Carapezza, EM TI External second gate, Fourier transform ion mobility spectrometry: Parametric optimization for detection of weapons of mass destruction SO SENSORS, AND COMMAND, CONTROL, COMMUNICATIONS, AND INTELLIGENCE(C31) TECHNOLOGIES FOR HOMELAND SECURITY AND HOMELAND DEFENSE III, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Command, Control, Communications and Intelligence (C31) Technologies for Homeland Security and Homeland Defense III CY APR 12-16, 2004 CL Orlando, FL SP SPIE AB Ion mobility spectrometry (IMS) is recognized as one of the most sensitive and robust techniques for the detection of narcotics, explosives and chemical warfare agents. IMS is widely used in forensic, military and security applications. Increasing threat of terrorist attacks, the proliferation of narcotics, Chemical Weapons Convention (CWC) treaty verification as well as humanitarian de-mining efforts have mandated that equal importance be placed on the time required to obtain results as well as the quality of the analytical data.((1)) In this regard IMS is virtually unrivaled when both speed of response and sensitivity have to be considered.((2)) The problem with conventional (signal averaging) IMS systems is the fixed duty cycle of the entrance gate that restricts to less than 1%, the number of available ions contributing to the measured signal. Furthermore, the signal averaging process incorporates scan-to-scan variations that degrade the spectral resolution contributing to misidentifications and false positives. With external second gate, Fourier Transform ion mobility spectrometry (FT-IMS) the entrance gate frequency is variable and can be altered in conjunction with other data acquisition parameters (scan time and sampling rate) to increase the spectral resolution to reduce false alarms and improve the sensitivity for early warning and contamination avoidance. In addition, with FT-IMS the entrance gate operates with a 50% duty cycle and so affords a seven-fold increase in sensitivity. Recent data on high explosives are presented to demonstrate the parametric optimization in sensitivity and resolution of our system. C1 Sandia Natl Labs, Analyt Mat Sci Dept, Livermore, CA 94551 USA. RP Tarver, EE (reprint author), Sandia Natl Labs, Analyt Mat Sci Dept, POB 969,Mail Stop 9403, Livermore, CA 94551 USA. NR 8 TC 1 Z9 1 U1 2 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5326-9 J9 P SOC PHOTO-OPT INS PY 2004 VL 5403 BP 395 EP 408 DI 10.1117/12.546800 PN 1-2 PG 14 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Optics; Physics, Applied; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Physics; Imaging Science & Photographic Technology GA BAZ63 UT WOS:000224321700043 ER PT S AU Wolford, JK Frank, MI Descalle, MA AF Wolford, JK Frank, MI Descalle, MA BE Carapezza, EM TI Modeling of fission neutrons as a signature for detection of highly enriched uranium SO SENSORS, AND COMMAND, CONTROL, COMMUNICATIONS, AND INTELLIGENCE(C31) TECHNOLOGIES FOR HOMELAND SECURITY AND HOMELAND DEFENSE III, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Sensors and Command, Control, Communications and Intelligence (C31) Technologies for Homeland Security and Homeland Defense III CY APR 12-16, 2004 CL Orlando, FL SP SPIE DE fissile material; radiation detection; threat reduction; neutron interrogation AB We present the results of modeling intended to evaluate the feasibility of using neutrons from induced fission in highly enriched uranium (HEU) as a means of detecting clandestine HEU, even when it is embedded in absorbing surroundings, such as commercial cargo. We characterized radiation from induced fission in HEU, which consisted of delayed neutrons at all energies and prompt neutrons at energies above a threshold. We found that for the candidate detector and for the conditions we considered, a distinctive HEU signature should be detectable, given sufficient detector size, and should be robust over a range of cargo content. In the modeled scenario, an intense neutron source was used to induce fissions in a spherical shell of HEU. To absorb, scatter, and moderate the neutrons, we place one layer of simulated cargo between the source and target and an identical layer between the target and detector. The resulting neutrons and gamma rays are resolved in both time and energy to reveal the portion arising from fission. We predicted the dominant reaction rates within calcium fluoride and liquid organic scintillators. Finally, we assessed the relative effectiveness of two common neutron source energies. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Wolford, JK (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5326-9 J9 P SOC PHOTO-OPT INS PY 2004 VL 5403 BP 609 EP 620 DI 10.1117/12.541015 PN 1-2 PG 12 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Optics; Physics, Applied; Imaging Science & Photographic Technology SC Computer Science; Engineering; Optics; Physics; Imaging Science & Photographic Technology GA BAZ63 UT WOS:000224321700065 ER PT J AU Arafat, HA Ahnert, F Pinto, NG AF Arafat, HA Ahnert, F Pinto, NG TI On the adsorption of aromatics on oxygenated activated carbon in nonaqueous adsorption media SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE activated carbon; surface treatment; oxidation; microcalorimetry; ultrasonic measurements ID AQUEOUS-SOLUTIONS; SURFACE SITES; PHENOL; MECHANISM AB In a previous study, H-bonding was postulated as a mechanism of adsorption for aromatics on oxygen-containing activated carbon. To verify this, the adsorption of phenol, aniline, benzene, and nitrobenzene was studied as a function of surface oxygen groups. It was determined that there is a linear correlation between total surface acidity and adsorption capacity for H-bonding adsorbates in cyclohexane. Flow microcalorimetry (FMC) and ultrasonic desorption tests also indicate stronger and less reversible adsorption bonds for H-bonding adsorbates. Reversibility of adsorption decreased with increasing surface oxygen concentration, indicating a strong relationship between the oxygen groups and adsorption mechanism. C1 Univ Cincinnati, Dept Chem & Mat Engn, Cincinnati, OH 45221 USA. Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Delft Univ Technol, Delft, Netherlands. RP Pinto, NG (reprint author), Univ Cincinnati, Dept Chem & Mat Engn, POB 210012, Cincinnati, OH 45221 USA. EM neville.pinto@uc.edu NR 28 TC 9 Z9 10 U1 0 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2004 VL 39 IS 1 BP 43 EP 62 DI 10.1081/SS-120027400 PG 20 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 777XR UT WOS:000189209600003 ER PT J AU Gramer, CJ Raymond, KN Jarvinen, GD Robison, TW Schroeder, NC Smith, BF AF Gramer, CJ Raymond, KN Jarvinen, GD Robison, TW Schroeder, NC Smith, BF TI The removal of Pu(IV) from aqueous solution using 2,3-dihydroxyterephthalamide-functionalized PEI with polymer filtration SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE polymer filtration; plutonium metal separations; catecholate ligands; ultrafiltration ID METAL-BINDING POLYMERS; SEQUESTERING AGENTS; SOLUBLE POLYMERS; ULTRAFILTRATION; PLUTONIUM; AMERICIUM; ACTINIDES; IONS; ENTEROBACTIN AB Polymer filtration (PF) uses a size-exclusion ultrafiltration membrane to retain higher molecular weight species while allowing the passage of smaller species through the membrane. Metal-ion separations from aqueous streams are accomplished with PF by using water-soluble chelating-polymers (WSCP), which are appropriately sized polymers that have covalently attached metal-binding ligands. In this study, a new WSCP was prepared by modifying polyethylenimine (PEI) through an amide linkage to attach 2,3-dihydroxyterephthalamide (TAM) groups that have high binding constants for high valent metal cations. The TAM ligand contains a dimethylethylenediamine side chain that was found to maintain polymer solubility throughout the working pH and ionic strength ranges studied. The new WSCP (designated PDT) showed selectivity for Pu(IV) over Am(III). For example, at pH 4.5, the distribution coefficient (D) was 1.6 x 10(3) for Am(III) (14% bound) and 1.3 x 10(6) for Pu(IV) (99.3% bound). The Pu(IV) D increased as a function of pH, and the highest D was 4.8 x 10(6) at pH 11.4, corresponding to 99.8% bound. Varying the PDT concentration from 0.1% to 0.001% had little effect on Pu(IV) D values. The high formation constant of the Pu(IV)-PDT complex appears to promote the oxidation of Pu(Ill) to Pu(IV), even in the presence of a high concentration of reductant, 0.25-M hydroxylamine nitrate (HAN). The same high formation constant allows the TAM-containing polymer to compete with plutonium polymer formation, as plutonium absorbed on the walls of a glass vessel dissolved after contacting it with PDT for 2 days. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Dept Chem, Div Chem Sci, Lawrence Berkeley Lab, Berkeley, CA USA. RP Schroeder, NC (reprint author), Los Alamos Natl Lab, Div Chem, MS J514, Los Alamos, NM 87545 USA. EM nschroeder@lanl.gov NR 23 TC 2 Z9 3 U1 1 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PD JAN PY 2004 VL 39 IS 2 BP 321 EP 339 DI 10.1081/SS-120027561 PG 19 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 801QT UT WOS:000220111100005 ER PT J AU McAlister, DR Dietz, ML Stepinski, D Zalupski, PR Dzielawa, JA Barrans, RE Hess, JN Herlinger, AW AF McAlister, DR Dietz, ML Stepinski, D Zalupski, PR Dzielawa, JA Barrans, RE Hess, JN Herlinger, AW TI Application of molecular connectivity indices to the design of supercritical carbon dioxide-soluble metal ion extractants: SC-CO2 Solubilities of symmetrically substituted alkylenediphosphonic acids SO SEPARATION SCIENCE AND TECHNOLOGY LA English DT Article DE SC-CO2; solubility; diphosphonic acid; seven- and eight-carbon ester; molecular connectivity ID DIPHOSPHONIC ACIDS; EXCHANGE RESIN; FLUID EXTRACTION; ORGANIC-COMPOUNDS; SOLID MATERIALS; LIGANDS; CO2; PREDICTION; LIQUIDS; HYDROCARBONS AB Using a dynamic flow method, the supercritical carbon dioxide (SC-CO2) solubilities of two series of symmetrically substituted alkylenediphosphonic acids, bearing 2-ethylhexyl and 3-trimethylsilyl-1-propyl ester groups, respectively, were determined as a function of the number of methylene groups separating the two phosphorus atoms. An even-odd effect, similar to that observed previously for the aggregation of these compounds in nonpolar diluents, was observed, with compounds that form more highly aggregated species in nonpolar diluents exhibiting lower solubility in SC-CO2. Differences in the relative solubilities of analogous members of these series prompted the study of the SC-CO2 solubilities of symmetrically substituted methylenediphosphonic acids bearing seven- and eight-carbon ester groups of various degrees of branching to determine the relative importance of steric and electronic effects in determining SC-CO2 solubilities. When molecular connectivity indices were used to quantify the extent of branching in the ester groups, a remarkable correlation between these molecular descriptors and SC-CO2 solubility was observed. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Loyola Univ, Dept Chem, Chicago, IL 60626 USA. RP Dietz, ML (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM mdietz@anl.gov NR 58 TC 2 Z9 2 U1 1 U2 4 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0149-6395 J9 SEPAR SCI TECHNOL JI Sep. Sci. Technol. PY 2004 VL 39 IS 4 BP 761 EP 780 DI 10.1081/SS-120028445 PG 20 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA 808OS UT WOS:000220579000002 ER PT B AU Wu, MS Kendall, RA Aluru, S AF Wu, MS Kendall, RA Aluru, S GP ieee computer society TI Exploring collective communications on a cluster of SMPs SO SEVENTH INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING AND GRID IN ASIA PACIFIC REGION, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on High Performance Computing and Grid in Asia Pacific Region (HPCAsia 2004) CY JUL 20-22, 2004 CL Omiya Sonic City, JAPAN SP SIGHPC, Informat Proc Soc Japan, IEEE CS Japan Chapter AB In this paper we investigate two strategies to improve the performance of collective communications on a cluster of SMPs. In the first part of the paper we explore the advantages and disadvantages of the commonly used strategy "optimize shared memory send and receive only". In the second part of the paper we show a model to design collective communications on SMP clusters which can be used to improve the disadvantages of the former strategy. Several collective operations are implemented through the later process, and the experimental results show better performance than vendor supplied implementations. C1 US DOE, Ames Lab, Dept Elect & Comp Engn, Ames, IA 50011 USA. RP Wu, MS (reprint author), US DOE, Ames Lab, Dept Elect & Comp Engn, Ames, IA 50011 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2138-X PY 2004 BP 114 EP 117 DI 10.1109/HPCASIA.2004.1324024 PG 4 WC Computer Science, Theory & Methods SC Computer Science GA BAS45 UT WOS:000223368300015 ER PT B AU Watson, GR Sottile, MJ Minnich, RG Choi, SE Hendriks, EA AF Watson, GR Sottile, MJ Minnich, RG Choi, SE Hendriks, EA GP ieee computer society TI Pink: A 1024-node single-system image Linux cluster SO SEVENTH INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING AND GRID IN ASIA PACIFIC REGION, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on High Performance Computing and Grid in Asia Pacific Region (HPCAsia 2004) CY JUL 20-22, 2004 CL Omiya Sonic City, JAPAN SP SIGHPC, Informat Proc Soc Japan, IEEE CS Japan Chapter AB This paper describes our experience of designing and building Pink, a 1024-node (2048 processor) Myrinet-based single-system image Linux cluster that was installed in January 2003 at the Los Alamos National Laboratory. At the time of its installation, Pink was the largest single-system image Linux cluster in the world, and was based entirely on open-source software - from the BIOS up. Pink was the proof-of-concept prototype for Lightning, a production 1408-node (2816 processor) cluster that will begin operation at LANL later this year. Lightning is currently number 6 on the Top500 list. In this paper we will examine the issues that were ncountered and the problems that needed to be overcome in order to scale a cluster to this size. We will also present some performance numbers that demonstrate the scalability and manageability of the cluster software suite. C1 Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87545 USA. RP Watson, GR (reprint author), Los Alamos Natl Lab, Adv Comp Lab, POB 1663,CCS-1, Los Alamos, NM 87545 USA. NR 7 TC 1 Z9 1 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2138-X PY 2004 BP 454 EP 461 DI 10.1109/HPCASIA.2004.1324076 PG 8 WC Computer Science, Theory & Methods SC Computer Science GA BAS45 UT WOS:000223368300066 ER PT B AU Hendriks, EA AF Hendriks, EA GP ieee computer society TI Fast mapping on Myrinet networks SO SEVENTH INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING AND GRID IN ASIA PACIFIC REGION, PROCEEDINGS LA English DT Proceedings Paper CT 7th International Conference on High Performance Computing and Grid in Asia Pacific Region (HPCAsia 2004) CY JUL 20-22, 2004 CL Omiya Sonic City, JAPAN SP SIGHPC, Informat Proc Soc Japan, IEEE CS Japan Chapter AB This paper presents an alternate method for discovering new switches and comparing switches when mapping a Myrinet network. Existing methods for mapping Myrinet networks rely on timeouts and are prone to false negatives due to network deadlock. Our algorithm increases the mapper's speed by providing a fast negative answer without relying on a timeout. In addition, the mapper's reliability is increased because it allows the mapper to detect if network deadlock has occurred. Mapping time on our 1024 port network has been reduced from approximately 7 minutes to 15 seconds. C1 Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87544 USA. RP Hendriks, EA (reprint author), Los Alamos Natl Lab, Adv Comp Lab, Los Alamos, NM 87544 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2138-X PY 2004 BP 462 EP 466 DI 10.1109/HPCASIA.2004.1324077 PG 5 WC Computer Science, Theory & Methods SC Computer Science GA BAS45 UT WOS:000223368300067 ER PT B AU Heilbronn, L Iwata, Y Murakami, T Iwase, H Nakamura, T Sato, H Ronningen, R AF Heilbronn, L Iwata, Y Murakami, T Iwase, H Nakamura, T Sato, H Ronningen, R GP oecd TI Neutron production measurements relevant to shielding for space-related activities SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp AB Neutron production cross-sections were measured from 290 MeV/nucleon C and 600 MeV/nucleon Ne interacting in a slab of simulated Martian regolith/polyethylene composite, and from 400 MeV/nucleon Ne interacting in a section of wall materials from the International Space Station. Neutron spectra were measured at seven angles between 5degrees and 80degrees, and for neutron energies 5 MeV and greater. Spectra at forward angles are dominated by the break-up of the projectile, whereas spectra at back angles show the typical exponential fall-off with energy that is indicative of decay from the overlap region and the target remnant. The measured total neutron production cross-sections indicate that the regolith/polyethylene composite may be a more effective shielding material than the ISS wall materials, in terms of the number of neutrons produced. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Heilbronn, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 2 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 99 EP 105 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000008 ER PT B AU Rokni, SH Gwise, T Liu, JC Fasso, A Roesler, S AF Rokni, SH Gwise, T Liu, JC Fasso, A Roesler, S GP oecd TI Induced radioactivity of materials by stray radiation fields at an electron accelerator SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp AB Samples of soil, water, aluminium, copper and iron were irradiated in the stray radiation field generated by the interaction of a 28.5 GeV electron beam in a copper dump in the Beam Dump East facility at the Stanford Linear Accelerator Center. The specific activity induced in the samples was measured by gamma spectroscopy and other techniques. In addition, the isotope production in the samples was calculated with detailed Monte Carlo simulations using the FLUKA code. The calculated activities are compared to the experimental values and differences are discussed. Taking the uncertainties in the measurements and simulations into account, the agreement of measured and calculated induced radioactivity within a factor of two, as is the case for half of the identified isotopes in this study, can be considered to be acceptable. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Rokni, SH (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 131 EP 142 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000011 ER PT B AU Mashnik, SG Prael, RE Sierk, AJ Gudima, KK Mokhov, NV AF Mashnik, SG Prael, RE Sierk, AJ Gudima, KK Mokhov, NV GP oecd TI Event generator benchmarking for proton radiography applications SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp ID P-PERPENDICULAR-TO; QUARK-GLUON STRINGS; NUCLEUS COLLISIONS; PARTICLE PRODUCTION; MODEL; HADRONS; INCIDENT; 70-GEV AB We have benchmarked the QGSM code and event generators of the MARS and LAHET3 codes as potential candidates for high-energy programs to be used in simulations for the Proton Radiography (PRad) Project. We have compiled from the literature experimental data on spectra of particles emitted from proton-induced reactions at incident energies from 30 GeV to 70 GeV on different nuclei and have performed calculations for all reactions for which we found data with these three codes without any modifications and using only default parameters and standard inputs. Our results (514 plots) show that all three codes reasonably describe most of the studied reactions, though all of them should be further improved before becoming reliable tools for PRad. We present here our conclusions concerning the relative roles of different reaction mechanisms in the production of specific secondary particles. We comment on the strengths and weaknesses of QGSM, MARS and LAHET3 and suggest further improvements to these codes and to other models. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 57 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 193 EP 205 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000017 ER PT B AU Job, PK Alderman, J AF Job, PK Alderman, J GP oecd TI Radiation levels experienced by the insertion devices of the third-generation synchrotron radiation sources SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp ID ND-FE-B; STORAGE RING PETRA; PERMANENT-MAGNETS; NEUTRON-IRRADIATION; DOSIMETERS AB Third-generation synchrotron radiation sources like the Advanced Photon Source (APS) use insertion devices made of Nd-Fe-B permanent magnets to produce X-rays for scientific research. The concern of radiation-induced demagnetisation of these insertion devices spurred a-project aimed to measure and analyse the radiation levels experienced by these insertion devices during the operation of synchrotron radiation sources. The project required a reliable photon high-dose dosimetry technique capable of measuring high integrated dose levels during one operational cycle. Radiachromic dosimeters were considered for this purpose. In collaboration with the National Institute of Standards and Technology (NIST) these dosimeters were tested, calibrated and used at the Advanced Photon Source. Prior to each run radiachromic dosimeters are placed on the upstream and downstream edges of the 2.5 m long insertion devices. Following each operational cycle these dosimeters are retrieved from the storage ring and optical density changes are analysed. The measurements are compared with previous estimates. The results show that the previous predictions grossly underestimate the radiation levels received by the insertion devices. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Job, PK (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 299 EP 304 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000026 ER PT B AU Hunter, HT Manneschmidt, JB Kirk, BL Greene, M Sartori, E Suzuki, T Vaz, P AF Hunter, HT Manneschmidt, JB Kirk, BL Greene, M Sartori, E Suzuki, T Vaz, P GP oecd TI Progress report on the available analytical tools for accelerator shielding analysis 2002 SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp AB Given the new developments in accelerators, especially spallation neutron sources, new analytical tools and applications have recently been developed, tested and used. An ongoing need exists to distribute the codes, their data and the benchmarks used in validating the design parameters for shielding energies and particles involved in the applications. What is presented is the fruit of the efforts of the data centres that identify, collect, test and disseminate the tools necessary for proper accelerator shielding analysis around the world. The OECD Nuclear Energy Agency Data Bank (NEA DB), the ORNL Radiation Safety Information Computational Center (RSICC) and the Research Organisation for Information Science and Technology (RIST) have continued to lead the European, American and Japanese nuclear communities, respectively, to state-of-the-art software and data that fit their needs. The following contains a listing of those tools that are available and most applicable to today's accelerator shielding analyses. C1 Oak Ridge Natl Lab, RSICC, Oak Ridge, TN 37831 USA. RP Hunter, HT (reprint author), Oak Ridge Natl Lab, RSICC, Oak Ridge, TN 37831 USA. RI Vaz, Pedro/K-2464-2013 OI Vaz, Pedro/0000-0002-7186-2359 NR 7 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 307 EP 336 PG 30 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000027 ER PT B AU Mashnik, SG Gudima, KK Sierk, AJ AF Mashnik, SG Gudima, KK Sierk, AJ GP oecd TI Merging the CEM2k and LAQGSM codes with GEM2 to describe Fission and light-fragment production SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp ID INTRANUCLEAR-CASCADE CALCULATION; HEAVY-ION COLLISIONS; QUARK-GLUON STRINGS; CROSS-SECTIONS; NUCLEAR-REACTIONS; KINETIC ENERGIES; MODEL; RESIDUES; EMISSION AB We present the current status of the improved Cascade-exciton Model (CEM) code CEM2k and of the Los Alamos version of the Quark-gluon String Model code LAQGSM. To describe fission and light-fragment (heavier than He-4) production, both CEM2k and LAQGSM have been merged with the GEM2 code of Furihata. We present some results on proton- and deuteron-induced spallation, fission and fragmentation reactions predicted by these extended versions of CEM2k and LAQGSM. We show that merging CEM2k and LAQGSM with GEM2 allows us to describe many fission and fragmentation reactions in addition to the spallation reactions, which are already relatively well described. Nevertheless, the standard version of GEM2 does not provide a completely satisfactory description of complex particle spectra, heavy-fragment emission and spallation yields, and is not yet a reliable tool for applications. We conclude that we may choose to use a model similar to the GEM2 approach in our codes, but it must be significantly extended and further improved. We observe that it is not sufficient to analyse only A and Z distributions of the product yields when evaluating this type of model, as is often done in the literature; instead it is important to study all the separate isotopic yields as well as the spectra of light particles and fragments. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mashnik, SG (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 62 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 337 EP 366 PG 30 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000028 ER PT B AU Mokhov, NV AF Mokhov, NV GP oecd TI Status of MARS code SO SHIELDING ASPECTS OF ACCELERATORS, TARGETS AND IRRADIATION FACILITIES, WORKSHOP PROCEEDINGS LA English DT Proceedings Paper CT 6th Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-6) CY APR 10-12, 2002 CL Menlo Pk, CA SP OECD Nucl Energy Agcy, Stanford Linear Accelerator Ctr, Radiat Safety Informat Computat Ctr, Reactor Phys Comm Japan, Shielding Working Grp ID MODEL AB Status and recent developments of the MARS 14 Monte Carlo code system for simulation of hadronic and electromagnetic cascades in shielding, accelerator and detector components in the energy range from a fraction of an electronvolt up to 100 TeV are described. These include physics models both in strong and electromagnetic interaction sectors, variance reduction techniques, residual dose, geometry, tracking, histogramming, MAD-MARS Beam Line Builder and Graphical-User Interface. The code is supported world-wide; for more information consult http://www-ap.fnal.gov/MARS/ and MARS discussion list mars-forum@fnal.gov. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Mokhov, NV (reprint author), Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 24 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-01733-X PY 2004 BP 407 EP 416 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA BAT89 UT WOS:000223535000033 ER PT S AU Chesnut, GN Streetman, BD Schiferl, D Anderson, WW Nico, M Meng, Y AF Chesnut, GN Streetman, BD Schiferl, D Anderson, WW Nico, M Meng, Y BE Furnish, MD Gupta, YM Forbes, JW TI Static X-ray diffraction study of cerium: The standard approach & the magic-angle approach SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID EQUATION-OF-STATE; HIGH-PRESSURE; LATTICE STRAINS; GPA; STRESS; CALIBRATION; ELASTICITY; STRENGTH; METAL; CELL AB Cerium, a member of the rare earth metals, has been studied up to 300 kilobars in a diamond-anvil cell using energy- and angular-dispersive x-ray diffraction with a synchrotron source. The purpose of this experiment was to examine the electronic and structural behavior of cerium and to examine the effects of deviatoric stress due to non-hydrostatic conditions within the sample environment. Using the standard sample orientation and data from various orientations, the effects of deviatoric stress are shown. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chesnut, GN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM gchesnut@lanl.gov; bstreet@lanl.gov NR 16 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 37 EP 40 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000006 ER PT S AU Chisolm, E Crockett, S Wallace, D AF Chisolm, E Crockett, S Wallace, D BE Furnish, MD Gupta, YM Forbes, JW TI Variation of thermal and cold curve contributions to thermodynamic functions along the Hugoniot SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We have developed a technique for constructing two-phase EOS for simple metals using lattice dynamics, liquid dynamics, and electronic structure theory, and we have tested this technique by constructing an EOS for Aluminum valid up to compressions over two,and temperatures up to five times melting temperature [Chisolm, Crockett, and Wallace, to appear in Phys. Rev. B]. Here we investigate the predictions of this EOS for the pressure, energy, and entropy along the Hugoniot up to roughly 5 Mbar, showing the relative contributions of the cold curve (T = 0 isotherm) and thermal part of the EOS to each function. We also comment on the possibility of taking data from different regions of the Hugoniot as tests of different terms in the EOS. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Chisolm, E (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. EM echisolm@lanl.gov; crockett@lanl.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 41 EP 44 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000007 ER PT S AU Crockett, S Chisolm, E Wallace, D AF Crockett, S Chisolm, E Wallace, D BE Furnish, MD Gupta, YM Forbes, JW TI A comparison of theory and experiment of the bulk sound velocity in aluminum using a two-phase EOS SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID ELASTIC-CONSTANTS; 2024-T4 ALUMINUM; SHOCK WAVES; ATTENUATION AB We compute the bulk sound speed along the Hugoniot using a new solid-liquid two-phase equation of state (EOS) for aluminum [Chisolm, Crockett, and Wallace, to appear in Phys. Rev. B] and compare with experimental sound speeds from various sources. The experiment extends from the crystal through the entire solid-liquid two-phase region. The EOS and data closely agree on where the Hugoniot passes through the two-phase region, which corresponds to where aluminum melts. The bulk sound speed in the crystal region is consistent with the data, given the uncertainty in the experimental procedure. We also estimate shear moduli by using the experimental longitudinal sound speed data and the calculated bulk modulus. The shear modulus satisfies the approximation G(S)/B-S=constant, within experimental error bars, throughout the crystal region on the Hugoniot. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Crockett, S (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM crockett@lanl.gov; echisolm@lanl.gov NR 19 TC 4 Z9 4 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 45 EP 48 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000008 ER PT S AU Foiles, SM AF Foiles, SM BE Furnish, MD Gupta, YM Forbes, JW TI DFT calculations of structural and thermodynamic properties of molten Sn: Zero-pressure isobar SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID HARD SPHERES; EQUATION AB The dynamic compression of molten metals including Sn is of current interest. In particular, experiments on the compression of molten Sn by Davis and Hayes will be described at this conference. Supporting calculations of the equation of state and structure of molten Sn as a function of temperature and pressure are in progress. The calculations presented are ab initio molecular dynamics simulations based on electronic density functional theory within the local density approximation. The equation of state and liquid structure factors for zero pressure are compared with existing experimental results. The good agreement in this case provides validation of the calculations. C1 Sandia Natl Labs, Albuquerque, NM 87145 USA. RP Foiles, SM (reprint author), Sandia Natl Labs, Albuquerque, NM 87145 USA. EM foiles@sandia.gov NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 57 EP 60 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000011 ER PT S AU Graf, MJ Greeff, CW Boettger, JC AF Graf, MJ Greeff, CW Boettger, JC BE Furnish, MD Gupta, YM Forbes, JW TI High-pressure Debye-Waller and Gruneisen parameters of gold and copper SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID METALS; EQUATION; STATE AB The lattice vibrations are determined in the quasi-harmonic approximation for elemental Au and Cu to twice their normal density by first-principles electronic band-structure calculations. It is found for these materials that the important moments of the phonon density of states can be obtained to high accuracy from short-ranged force constant models. We discuss the implications for the Gruneisen parameters on the basis of calculated phonon moments and their approximations by using bulk moduli and Debye-Waller factors. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Graf, MJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM graf@lanl.gov; greeff@lanl.gov RI Greeff, Carl/N-3267-2013 NR 14 TC 8 Z9 8 U1 1 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 65 EP 68 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000013 ER PT S AU Knudson, MD Hanson, DL Bailey, JE Hall, CA Deeney, C Asay, JR AF Knudson, MD Hanson, DL Bailey, JE Hall, CA Deeney, C Asay, JR BE Furnish, MD Gupta, YM Forbes, JW TI Equation of state measurements in liquid deuterium to 100 GPA SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID INSULATOR-METAL TRANSITION; MOLECULAR-HYDROGEN; DENSE HYDROGEN; HUGONIOT; HOT AB Using intense magnetic pressure, a method was developed to launch flyer plates to velocities in excess of 20 km/s. This technique was used to perform plate-impact, shock wave experiments on cryogenic liquid deuterium (LD2) to examine its high-pressure equation of state (EOS). Using an impedance matching method, Hugoniot measurements were obtained in the pressure range of 22-100 GPa. The results of these experiments disagree with previously reported Hugoniot measurements of LD2 in the pressure range above similar to40 GPa, but are in good agreement with first principles, ab-initio models for hydrogen and its isotopes. Additionally, a novel approach was developed using a wave reverberation technique to probe density compression of LD2 along the principal Hugoniot. Relative transit times of shock waves reverberating within the sample are shown to be sensitive to the compression due to the first shock. Results in the range of 22-75 GPa corroborate the similar to4 fold density compression inferred from the impedance matching Hugoniot measurements, and provide data to differentiate between proposed theories for hydrogen and its isotopes. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Knudson, MD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mdknuds@sandia.gov; henson@lanl.gov; cdeene@sandia.gov; bwa@lanl.gov NR 23 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 81 EP 86 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000017 ER PT S AU Luo, SN Swift, DC Tierney, T Xia, KW Tschauner, O Asimow, PD AF Luo, SN Swift, DC Tierney, T Xia, KW Tschauner, O Asimow, PD BE Furnish, MD Gupta, YM Forbes, JW TI Time-resolved x-ray diffraction investigation of superheating-melting of crystals under ultrafast heating SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The maximum superheating of a solid prior to melting depends on the effective dimensionless nucleation energy barrier, heterogeneities such as free surfaces and defects, and heating rates. Superheating is rarely achieved with conventional slow heating due to the dominant effect of heterogeneous nucleation. In present work, we investigate the superheating-melting behavior of crystals utilizing ultrafast heating techniques such as exploding wire and laser irradiation, and diagnostics such as time-resolved X-ray diffraction combined with simultaneous measurements on voltage and current (for exploding wire) and particle velocity (for laser irradiation). Experimental designs and preliminary results are presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Luo, SN (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM dswift@lanl.gov; tomt@lanl.gov RI Asimow, Paul/E-7451-2010 OI Asimow, Paul/0000-0001-6025-8925 NR 6 TC 2 Z9 2 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 95 EP 98 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000020 ER PT S AU Saumon, A Guillot, T AF Saumon, A Guillot, T BE Furnish, MD Gupta, YM Forbes, JW TI Shock compression of deuterium at MBAR pressures and the interior of jupiter SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID EQUATION-OF-STATE; LIQUID DEUTERIUM; GIANT PLANETS; SATURN; HYDROGEN; MODELS; TRANSITION; GAS AB It is of great interest to planetary science to understand how the current experimental uncertainty on the hydrogen EOS affects the inferred structure of Jupiter. In particular, the mass of a core of heavy elements (other than H and He) and the total amount and distribution of heavy elements are very sensitive to the EOS of hydrogen and constitute important clues to its formation process. We present a study of the range of structures allowed by the current uncertainty in the hydrogen EOS. We show that an improved experimental understanding of hydrogen at Mbar pressures is necessary to put firm limits on the internal structure of Jupiter. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Saumon, A (reprint author), Los Alamos Natl Lab, MS F699, Los Alamos, NM 87545 USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 115 EP 118 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000025 ER PT S AU Swift, D Paisley, D Knudson, M AF Swift, D Paisley, D Knudson, M BE Furnish, MD Gupta, YM Forbes, JW TI Equation of state measurements for beryllium in the ICF capsule regime SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The dynamic response of beryllium on nanosecond time scales is important for controlling symmetry during the implosion of the fuel capsule in inertial confinement fusion. Particularly important is the behavior up to about 200 GPa, covering the foot of the implosion drive. We have performed experiments to measure the equation of state (EOS) and flow stress of beryllium, and to investigate solid-solid phase transitions and melting, using flyer impact and isentropic compression by pulsed electromagnetic fields at Z, and shocks induced by direct laser irradiation at TRIDENT. The principal diagnostic was VISAR velocimetry; transient x-ray diffraction was also used on some TRIDENT experiments. The Hugoniot and isentrope data were consistent with previously-reported EOS. The flow stress was inferred from elastic precursor waves to be about 6 GPa in the (0001) direction on these time scales, with significant sensitivity to orientation. Possible evidence was observed of the hex-bcc transition and of melting. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Swift, D (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM dswift@lanl.gov NR 6 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 119 EP 122 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000026 ER PT S AU Hare, DE Reisman, DB Garcia, F Green, LG Forbes, JW Furnish, MD Ha, C Hickman, RJ AF Hare, DE Reisman, DB Garcia, F Green, LG Forbes, JW Furnish, MD Ha, C Hickman, RJ BE Furnish, MD Gupta, YM Forbes, JW TI The isentrope of unreacted LX-04 to 1170 kbar SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID COMPRESSION EXPERIMENTS; Z-ACCELERATOR AB We present new data on the unreacted approximate isentrope of the HMX-based explosive LX-04, measured to 170 kbar, using newly developed long pulse isentropic compression techniques at the Sandia National Laboratories Z Machine facility. This study extends in pressure by 70% the previous state of the art on unreacted LX-04 using this technique. This isentrope will give the unreacted Hugoniot from thermodynamic relations using a Gruneisen equation of state model. The unreacted Hugoniot of LX-04 is important in understanding the structure of the reaction front in the detonating explosive. We find that a Hugoniot given by U-S = 2.95 km/s + 1.69 u(P) yields for an isentrope a curve which fits our LX-04 ICE data well. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hare, DE (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM hare2@llnl.gov NR 12 TC 3 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 145 EP 148 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000032 ER PT S AU Sewell, TD Menikoff, R AF Sewell, TD Menikoff, R BE Furnish, MD Gupta, YM Forbes, JW TI Complete equation of state for beta-HMX and implications for initiation SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A thermodynamically consistent equation of state for beta-HMX, the stable ambient polymorph of HMX, is developed that fits isothermal compression data and the temperature dependence of the specific heat computed from molecular dynamics. The equation of state is used to assess hot-spot conditions that would result from hydrodynamic pore collapse in a shock-to-detonation transition. The hot-spot temperature is determined as a function of shock strength by solving two Riemann problems in. sequence: first for the velocity and density of the jet formed when the shock overtakes the pore, and second for the stagnation state when the jet impacts the far side of the pore. For a shock pressure below 5 GPa, the stagnation temperature from the jet is below the melt temperature at ambient pressure and hence insufficient for rapid reaction. Consequently, for weak shocks a dissipation mechanism in addition to shock heating is needed to generate hot spots. When the stagnation temperature is sufficiently high for rapid reaction,, the shock emanating from the hot spot is computed, assuming a constant volume bum. For initial shocks below 20 GPa, the temperature behind the second shock is below 1000 K and would not propagate a detonation wave. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sewell, TD (reprint author), Los Alamos Natl Lab, Div Theoret, MS-B214, Los Alamos, NM 87545 USA. EM rtm@lanl.gov NR 9 TC 4 Z9 4 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 157 EP 160 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000035 ER PT S AU Davis, JP Hayes, DB AF Davis, JP Hayes, DB BE Furnish, MD Gupta, YM Forbes, JW TI Isentropic compression experiments on dynamic solidification in tin SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID PHASES; WAVE AB Isentropic compression experiments were performed on molten tin (initial temperature 500-600 K), using the Sandia Z Accelerator to generate magnetically driven, planar ramp waves compressing the tin across the equilibrium liquid-solid phase boundary. Velocity interferometry measured time-resolved wave profiles at the tin/window interface. The experiments exhibit a departure from expected liquid response, time-dependent behavior above 8 GPa, and, at higher pressure, reduced wave speed relative to calculations using a nonequilibrium phase-mixture model. These phenomena may be due to a nonequilibrium solidification process, but verification of this conjecture will require further work. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Davis, JP (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jpdavis@sandia.gov; dennis@nmia.com NR 10 TC 5 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 163 EP 166 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000036 ER PT S AU Luo, SN Ahrens, TJ Swift, DC AF Luo, SN Ahrens, TJ Swift, DC BE Furnish, MD Gupta, YM Forbes, JW TI Melting at the limit of superheating SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Theories on superheating-melting mostly involve vibrational and mechanical instabilities, catastrophes of entropy, volume and rigidity, and nucleation-based kinetic models. The maximum achievable superheating is dictated by nucleation process of melt in crystals, which in turn depends on material properties and heating rates. We have established the systematics for maximum superheating by incorporating a dimensionless nucleation barrier parameter and heating rate, with which systematic molecular dynamics simulations and dynamic experiments are consistent. Detailed microscopic investigation with large-scale molecular dynamics simulations of the superheating-melting process, and structure-resolved ultrafast dynamic experiments axe necessary to establish the connection between the kinetic limit of superheating and vibrational and mechanical instabilities, and catastrophe theories. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Luo, SN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM tja@caltech.edu; dswift@lanl.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 172 EP 175 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000038 ER PT S AU Samara, GA AF Samara, GA BE Furnish, MD Gupta, YM Forbes, JW TI From ferroelectric to quantum paraelectric: KTa1-xNbxO3 (KTN), a model system SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The mixed perovskite oxides KTa1-xNbxO3, or KTN, are a model system for studying ferroelectric behavior and phase transitions under pressure. Crystals with x > 0.1 exhibit ferroelectric soft-mode behavior and a sequence of phase transitions, while for x less than or equal to 0.02 a pressure-induced ferroelectric-to-relaxor crossover occurs. The system also exhibits a pressure-induced crossover from classical-to-quantum behavior ultimately leading to the complete suppression of the phase transition and the formation of a quantum paraelectric state. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Samara, GA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM gasamar@sandia.gov NR 8 TC 1 Z9 1 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 176 EP 179 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000039 ER PT S AU Setchell, RE Tuttle, BA Voigt, JA AF Setchell, RE Tuttle, BA Voigt, JA BE Furnish, MD Gupta, YM Forbes, JW TI Microstructural effects on the shock response of PZT 95/5 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Shock-induced depoling of the ferroelectric ceramic PZT 95/5 is utilized in pulsed power devices. The bulk density and corresponding porous microstructure can be varied by adding different types and quantities of organic pore formers prior to bisque firing and sintering. In previous studies, a baseline material having a particular microstructure was examined in detail. Comparative experiments with a second material having a common density but a very different porous microstructure showed only subtle differences in mechanical and electrical shock properties. However, large differences in these properties were observed using materials prepared over a range of bulk densities. Recent studies have examined three new materials that were prepared at a common density matching that of the baseline material. Each was made using spherical pore formers having diameters within a narrow range, with nominal diameters varying from 15 pm to 140 pm. Normally poled samples of each material were used in identical planar impact experiments that produced peak stresses of 2.5 GPa under high-field conditions, or 4.5 GPa under short-circuit conditions. Unlike previous comparisons of common-density materials, consistent trends were evident in depoling currents, wave rise times and amplitudes, and yielding thresholds. Overall differences between two of these materials and the baseline material were relatively small, but the material made with the smallest pore former showed significant differences. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Setchell, RE (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM resetch@sandia.gov NR 3 TC 3 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 180 EP 183 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000040 ER PT S AU Bardenhagen, SG Greening, DR Roessig, KM AF Bardenhagen, SG Greening, DR Roessig, KM BE Furnish, MD Gupta, YM Forbes, JW TI The material point method and simulation of wave propagation in heterogeneous media SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The mechanical response of polycrystalline materials, particularly under shock loading, is of significant interest in a variety of munitions and industrial applications. Homogeneous continuum models have been developed to describe material response, including Equation of State, strength, and reactive bum models. These models provide good estimates of bulk material response. However, there is little connection to underlying physics and, consequently, they cannot be applied far from their calibrated regime with confidence. Both explosives and metals have important structure at the (energetic or single crystal) grain scale. The anisotropic properties of the individual grains and the presence of interfaces result in the localization of energy during deformation. In explosives energy localization can lead to initiation under weak shock loading, and in metals to material ejecta under strong shock loading. To develop accurate, quantitative and predictive models it is imperative to develop a sound physical understanding of the grain-scale material response. Numerical simulations are performed to gain insight into grain-scale material response. The Generalized Interpolation Material Point Method family of numerical algorithms, selected for their robust treatment of large deformation problems and convenient framework for implementing material interface models, are reviewed. A three-dimensional simulation of wave propagation through a granular material indicates the scale and complexity of a representative grain-scale computation. Verification and validation calculations on model bi-material systems indicate the minimum numerical algorithm complexity required for accurate simulation of wave propagation across material interfaces and demonstrate the importance of interfacial decohesion. Preliminary results are presented which predict energy localization at the grain boundary in a metallic bicrystal. C1 Los Alamos Natl Lab, Grp T14, Los Alamos, NM 87545 USA. RP Bardenhagen, SG (reprint author), Los Alamos Natl Lab, Grp T14, MS B214, Los Alamos, NM 87545 USA. EM bard@lanl.gov NR 6 TC 0 Z9 0 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 187 EP 192 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000041 ER PT S AU Greeff, CW Rigg, PA Knudson, MD Hixson, RS Gray, GT AF Greeff, CW Rigg, PA Knudson, MD Hixson, RS Gray, GT BE Furnish, MD Gupta, YM Forbes, JW TI Modeling dynamic phase transitions in Ti and Zr SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID TRANSFORMATION; PRESSURE; TITANIUM; ZIRCONIUM; KINETICS; METAL AB Both Ti and Zr exhibit phase transitions from the alpha (hcp) to the omega phase at pressures of a few GPa. In addition, the Hugoniot of Zr shows a second phase transition at 23 GPa. We have developed multiphase equations of state for these metals based on ultrasonic, static compression, and shock data. The second transition in Zr is consistent with a phase diagram in which the high-temperature and high-pressure bcc phases are a single continuous phase. Time-resolved experiments using plate impact and continuous magnetic loading are compared to simulations to investigate the kinetics of these phase transitions. Strong kinetic effects are observed in the alpha - omega transition in both metals, with the dynamic phase transition observed at pressures well above the equilibrium phase boundary. Data on Zr samples of varied purity are consistent with a strong reduction of the transformation rate by impurities. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Greeff, CW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM greeff@lanl.gov RI Greeff, Carl/N-3267-2013 NR 11 TC 5 Z9 6 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 209 EP 212 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000046 ER PT S AU Greening, DR Koskelo, A AF Greening, DR Koskelo, A BE Furnish, MD Gupta, YM Forbes, JW TI Calculation of grain boundary shock interactions SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB As part of a larger project into the interactions of shock with grain boundaries, calculations that show a localization of energy in some configurations were performed. The verification and prediction of these localizations become important, due to their role in the initiation of a variety of significant material process. The prototype problem is a single grain boundary, inclined to the direction of shock propagation, separating regions of differing orientation. The calculations are made with a finite volume code using a continuum material model with explicit elastic, and plastic anisotropy. The response of NiAl is simulated using material property data front published sources, and from new experiments performed as part of the over-all project. The localization is seen internally as a small region of higher pressure at the intersection of the shock and the grain boundary. At the breakout surface the localization becomes manifest in velocity and displacement excursions at the grain boundary. This surface phenomenon provides an observable that can be used, with planned experiments, to validate the predictive behavior of the model. C1 Los Alamos Natl Lab, Mat Sci Grp, Div Appl Phys, Los Alamos, NM 87545 USA. RP Greening, DR (reprint author), Los Alamos Natl Lab, Mat Sci Grp, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. EM greenfield@lanl.gov NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 213 EP 216 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000047 ER PT S AU Kadau, K Germann, TC Lomdahl, PS Holian, BL Cherne, FJ AF Kadau, K Germann, TC Lomdahl, PS Holian, BL Cherne, FJ BE Furnish, MD Gupta, YM Forbes, JW TI Atomistic simulations of shock-induced phase transitions SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID MOLECULAR-DYNAMICS SIMULATIONS; WORLDS FASTEST COMPUTER; ONE BILLION ATOMS; ORIENTATION DEPENDENCE; MATERIALS FAILURE; WAVES; IMPURITIES; METALS; IRON AB We report on large scale non-equilibrium atomistic simulations of shock-induced solid-solid phase transformations. As an example the alpha --> epsilon transformation in iron and the A11 (GaI)-->cI12 (GaII) transformation in gallium are discussed. The use of semi-empirical descriptions of the inter-atomic forces and today's parallel computing resources allow for a quantitative comparison of the theoretically calculated data with the experimental results. The discussion will include the crystallographic orientation dependence on the transformation process in single crystals. Simulations containing several millions of iron atoms reveal that above a critical shock strength, many small close-packed grains nucleate in the shock-compressed bcc crystal. For shock waves in the [001] direction the initially small grains are growing on a picosecond time scale to form larger, energetically favored, grains. For the two other major crystallographic directions, here the annealing processes are slower and and have not finished within the time scales accessible with atomistic simulations (up to 50 ps). Furthermore, crystals shocked in [111] direction produce solitary waves ahead of the actual shock front. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kadau, K (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM kkadau@lanl.gov NR 28 TC 1 Z9 1 U1 3 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 229 EP 234 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000051 ER PT S AU Koskelo, A Greenfield, S Greening, D Swift, D AF Koskelo, A Greenfield, S Greening, D Swift, D BE Furnish, MD Gupta, YM Forbes, JW TI New windows into shocks at the mesoscale SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID LASER IRRADIATION AB This paper presents experimental observation and modeling of time dependent energy localization occurring when a shock propagates along and through a grain boundary. This work is part of a larger program of investigation of the effect of grain boundaries on shock propagation in materials. The project is initially focused on the simplest of materials: a bicrystal. Our study covers the effects of grain orientation, the grain boundary angle, the boundary region, shock properties and the interplay between these in determining the characteristics of shock propagation. Ultimately, we will use this information as a basis for incorporation into models of polycrystalline materials. Some of the physics found in polycrystals is absent, but the use of simple, well-defined samples allows thorough measurements to be made. Laser-based experiments and diagnostics are used throughout, permitting us to perform the many experiments required in an economical way. NiAl was chosen as a suitable anisotropic material; single crystal and bicrystal samples were prepared. The EOS and single-crystal elasticity were estimated with ab fere initio quantum mechanics. Laser flyer impact and direct drive experiments, coupled with line-imaging VISAR, were used to test and refine the EOS, and to measure crystal plasticity. Initial models of bicrystals under shock loading have been developed, shock experiments have been conducted on bicrystals and recovered samples have been analyzed. C1 Los Alamos Natl Lab, Adv Diagnost & Instrumentat Grp, Div Chem, Los Alamos, NM 87545 USA. RP Koskelo, A (reprint author), Los Alamos Natl Lab, Adv Diagnost & Instrumentat Grp, Div Chem, POB 1663, Los Alamos, NM 87545 USA. EM greenfield@lanl.gov; dswift@lanl.gov NR 9 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 239 EP 242 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000053 ER PT S AU Cherne, FJ Baskes, MI Germann, TC Ravelo, RJ Kadau, K AF Cherne, FJ Baskes, MI Germann, TC Ravelo, RJ Kadau, K BE Furnish, MD Gupta, YM Forbes, JW TI Shock hugoniot and melt curve for a modified embedded atom method model of gallium SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID METALS; IMPURITIES; POTENTIALS; STATE; GA AB Molecular dynamics (MD) simulations have been performed on the complex material gallium using a literature modified embedded atom method (MEAM) potentials which reproduces the unusual behavior of this element. Both liquid and solid properties will be examined using the equilibrium MD "Hugoniostat" method and molecular statics. The calculated pressure dependence of the melt curve is found to agree well with experiment. The calculated Hugoniot is in reasonable agreement with the experimental Hugoniot EOS even better agreement can be obtained through a slight modification of the MEAM parameters. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cherne, FJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM cheme@lanl.gov; tcg@lanl.gov; ravelo@lanl.gov; kkadau@lanl.gov NR 16 TC 4 Z9 4 U1 2 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 281 EP 284 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000063 ER PT S AU Germann, TC Hammerberg, JE Holian, BL AF Germann, TC Hammerberg, JE Holian, BL BE Furnish, MD Gupta, YM Forbes, JW TI Large-scale molecular dynamics simulations of ejecta formation in copper SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SHOCK-WAVES AB Non-equilibrium molecular dynamics simulations are used to investigate the ejection of matter which takes place when a planar shock wave encounters a free surface. We will focus on Cu fcc single crystals, using an empirical embedded-atom method interatomic potential, and present results for the ejecta mass dependence on shock strength, as well as size and velocity distributions. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Germann, TC (reprint author), Los Alamos Natl Lab, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. EM tcg@lanl.gov; jeh@lanl.gov; blh@lanl.gov NR 15 TC 25 Z9 27 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 285 EP 288 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000064 ER PT S AU Kress, JD Mazevet, S Collins, LA Blottiau, P AF Kress, JD Mazevet, S Collins, LA Blottiau, P BE Furnish, MD Gupta, YM Forbes, JW TI Quantum molecular dynamics simulations of shocked molecular liquids SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID METALS AB Using Quantum Molecular Dynamics, we study the dissociation of nitrogen oxide (NO) and carbon monoxide (CO) along both the principal and reshocked Hugoniots. We obtain good agreement with experimental data in terms of pressure and density. As the molecules dissociate at high pressure and temperatures, we characterize the myriad of species that form. As NO dissociates along both the principal and reshocked Hugoniot, a significant amount of molecular nitrogen forms. As CO dissociates along the principal Hugoniot, first at low pressures, CO2 forms and large particles form (both polymer chains and rings) that contain both carbon and oxygen. At higher pressures (above 30 GPa), the CO2 dissociates and the particles breakup and form a mixture of CO, atomic carbon, and small transient clusters with lifetimes less than a typical molecular vibrational period. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Kress, JD (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM jdk@lanl.gov; smazevet@lanl.gov NR 12 TC 5 Z9 5 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 289 EP 292 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000065 ER PT S AU Mazevet, S Kress, JD Magee, NH Keady, JJ Collins, LA AF Mazevet, S Kress, JD Magee, NH Keady, JJ Collins, LA BE Furnish, MD Gupta, YM Forbes, JW TI Quantum Molecular Dynamics calculations of rosseland mean opacities SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID AUGMENTED-WAVE METHOD; ULTRASOFT PSEUDOPOTENTIALS; TRANSITION; DEUTERIUM; METALS AB We show that Quantum Molecular Dynamics provides a powerful tool to extend and benchmark current opacity libraries into the complex regime of warm dense matter. In this regime, the medium can be constituted of electrons, protons, atoms and molecules, while plasma and many body effects can not be treated as perturbations. Among the most notable features of this new approach for calculating Rosseland mean opacities is the ability to obtain a consistent set of material, optical and electrical properties for various mixtures from the same simulation. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Mazevet, S (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM smazevet@lanl.gov; jdk@lanl.gov NR 23 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 293 EP 297 PG 5 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000066 ER PT S AU Patel, MV Streitz, FH AF Patel, MV Streitz, FH BE Furnish, MD Gupta, YM Forbes, JW TI Simulations of rapid pressure-induced solidification in molten metals SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID ATOMISTIC SIMULATION AB The process of interest in this study is the solidification of a molten metal subjected to rapid pressurization. Most details about solidification occurring when the liquid-solid coexistence line is suddenly transversed along the pressure axis remain unknown. We present preliminary results from an ongoing study of this process for both simple models of metals (Cu) and more sophisticated material models (MGPT potentials for Ta). Atomistic (molecular dynamics) simulations are used to extract details such as the time and length scales that govern these processes. Starting with. relatively simple potential models, we demonstrate how molecular dynamics can be used to study solidification. Local and global order parameters that aid in characterizing the phase have been identified, and the dependence of the solidification time on the phase space distance between the final (PT) state and the coexistence line has been characterized. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Patel, MV (reprint author), Lawrence Livermore Natl Lab, L-045,7000 East Ave, Livermore, CA 94550 USA. EM mehul@llnl.gov; streitz1@llnl.gov NR 9 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 298 EP 301 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000067 ER PT S AU Chitanvis, SM AF Chitanvis, SM BE Furnish, MD Gupta, YM Forbes, JW TI Hotspot mechanisms in shock-melted explosives SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB This report is a review of various initiation mechanisms in shock-melted explosives. This paper focuses on pre-ignition phenomena which cause a local temperature rise when a single void in HMX collapses under the action of a shock wave. Working in the melting regime, a timeline can be associated with the collapse of a single void, through a consideration of the time scales on which these mechanisms are activated. We have studied the hydrodynamic mechanism, in which the shock driven incident side of the void impinges on the shadow side of the void, and is brought to rest, causing a considerable temperature rise in the HMX. Clearly this mechanism comes into consideration after the void collapses completely. Another mechanism we studied is that of shear heating. It is important for extremely small voids, or for large voids after the void has been compressed to a sufficiently small scale. This mechanism comes into play after the void has collapsed, and a remnants of the void have been spun off into a vortex. The phenomenon of gas compression as the gas-filled void collapses is difficult to ignore, in view of the fact that large temperatures are generated by this mechanism. We speculate that this mechanism could be important if the initial, endothermic induction step in a reaction scheme is shorter than the time of collapse. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Chitanvis, SM (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 7 TC 2 Z9 3 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 319 EP 322 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000071 ER PT S AU Fried, LE Reed, EJ Manaa, MR AF Fried, LE Reed, EJ Manaa, MR BE Furnish, MD Gupta, YM Forbes, JW TI Simulations of fluid nitromethane under extreme conditions SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID INITIO MOLECULAR-DYNAMICS; SOLID NITROMETHANE; NEAT NITROMETHANE; HIGH-PRESSURE; ACI ION; SPECTROSCOPY; TEMPERATURE AB We report density functional molecular dynamics simulations to determine the early chemical events of hot (T = 3000 K) and dense (1.97 g/cm(3), V/V-0 = 0.68) nitromethane (CH3NO2). The first step in the decomposition process is an intermolecular proton abstraction mechanism that leads to the formation of CH3NO2H and the aci ion H2CNO2- in support of evidence from static high-pressure and shock experiments. An intramolecular hydrogen transfer that transforms nitromethane into the aci acid form, CH2NO2H, accompanies this event. This is the first confirmation of chemical reactivity with bond selectivity for an energetic material near the condition of fully reacted specimen. We also report the decomposition mechanism followed up to the formation of H2O as the first stable product. C1 Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP Fried, LE (reprint author), Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, L-282, Livermore, CA 94550 USA. EM fried1@llnl.gov; evan@mit.edu; manaa1@llnl.gov RI Fried, Laurence/L-8714-2014 OI Fried, Laurence/0000-0002-9437-7700 NR 20 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 327 EP 330 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000073 ER PT S AU Hamate, Y Horie, Y AF Hamate, Y Horie, Y BE Furnish, MD Gupta, YM Forbes, JW TI A statistical approach on mechanistic modeling of high-explosive ignition SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB This paper presents the development of a mechanistic reactive bum model for solid explosives through use of a size distribution function for hotspots. The model couples the unifying hot-spot model developed earlier and the Lagrangian hydrodynamic flow equations. The hot-spot model incorporates key features of energy localization without introducing the mechanism-specific traits and is applicable to the three primary mechanisms of energy localization: pore collapse, friction. and shear banding. The coupling of the model to the hydrodynamic flow equations include models for energy localization, the growth of hot spots, and a two-phase aggregation of distributed hot spots, and a mixing rule for a product gas and a reacting solid. Proof-of-concept calculations for shock initiation are carried out in one spatial dimension, using RDX as a model material. Results include (1) shock ignition and growth-to-detonation, and (2) quenching. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Hamate, Y (reprint author), Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. EM hamate@lanl.gov; horie@lanl.gov NR 10 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 335 EP 338 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000075 ER PT S AU Howe, PM Benson, DJ AF Howe, PM Benson, DJ BE Furnish, MD Gupta, YM Forbes, JW TI Progress in the development of a shock initiation model SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We used an Eulerian hydrocode to guide the development of an engineering model of shock initiation. The model in its current form has two types of hotspots- one from void collapse, and one from interactions at grain boundaries. The dependence of hotspot and bulk temperatures upon shock strength is estimated using a Gruneisen equation of state for the bulk solid, calibrated against measurements of reaction times for steady state detonation. Arrhenius kinetics are used to predict ignition times associated with hotspot temperatures. The hotspots contribute a small amount of energy to the shock front, thereby causing some shock front acceleration, and also serve to initiate erosive burning. The two erosive bum reactions that result from the two different types of hotspots compete to consume the material. The energy release rate resulting from the competition of these reactions was used as input to a method of characteristics code. This in turn was used to calculate particle velocity time profiles at various simulated gauge locations. These calculated profiles were compared with experiment. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Howe, PM (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM pmhome@lanl.gov NR 7 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 343 EP 346 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000077 ER PT S AU Kaneshige, MJ Renlund, AM Schmitt, RG Erikson, WW AF Kaneshige, MJ Renlund, AM Schmitt, RG Erikson, WW BE Furnish, MD Gupta, YM Forbes, JW TI Development of scalable cook-off models using real-time in situ measurements SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Scalable thermal runaway models for cook-off of energetic materials (EMs) require realistic temperature- and pressure-dependent chemical reaction rates. The Sandia Instrumented Thermal Ignition apparatus was developed to provide in situ small-scale test data that address this model requirement. Spatially and temporally resolved internal temperature measurements have provided new insight into the energetic reactions occurring in PBX 9501, LX-10-2, and PBXN-109. The data have shown previously postulated reaction steps to be incorrect and suggest previously unknown reaction steps. Model adjustments based on these data have resulted in better predictions at a range of scales. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kaneshige, MJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mjkanes@sandia.gov NR 7 TC 5 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 351 EP 354 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000079 ER PT S AU Libersky, LD Randles, PW Bourne, N Vignjevic, R AF Libersky, LD Randles, PW Bourne, N Vignjevic, R BE Furnish, MD Gupta, YM Forbes, JW TI Simulation of void collapse in ammonium nitrate using a meshfree Lagrangian particle method SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID CAVITY AB A meshfree Lagrangian particle code is used to simulate void collapse in Ammonium Nitrate. A 4.3 GPa shock is introduced into the emulsion through impact with a PMMA flyer traveling at 2 mm/mus. The jet created by the shock-induced void collapse is examined, and the temperature in the region where the jet impacts the opposite side of the void is estimated. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Libersky, LD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM libersky@lanl.gov; n.k.bourne@nncs.cranfield.ac.uk NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 371 EP 374 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000084 ER PT S AU Mas, EM Clements, BE George, DC AF Mas, EM Clements, BE George, DC BE Furnish, MD Gupta, YM Forbes, JW TI Direct numerical simulations of PBX 9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We have explicitly gridded HMX crystals in PBX 9501 from 25 mum in diameter up to similar to.5 mm. We used HMX particle size distributions found in the literature to determine the relative numbers of different sized particulates. We applied our modified Mori-Tanaka theory to model the smaller crystals embedded in the plasticized estane binder (the dirty-binder). This model was modified to accommodate the large amount of HMX in the dirty binder. We then subjected the similar to1 million element PBX 9501 realization to boundary conditions commensurate with a Split Hopkinson Pressure Bar experiment. We compare results to experiment and a micro-mechanical model we have reported on earlier. We also discuss the information which can be extracted from these direct numerical simulations. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Mas, EM (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM mas@lanl.gov NR 11 TC 2 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 389 EP 392 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000088 ER PT S AU Menikoff, R AF Menikoff, R BE Furnish, MD Gupta, YM Forbes, JW TI Pore collapse and hot spots in HMX SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Hot spots are critical for initation of explosives because reaction rates are very temperature sensitive. For a plastic-bonded explosive, shock desensitization experiments imply that hot spots generated by pore collapse dominate shock initiation. Here, for the collapse of a single pore driven by a shock, the dependence of the temperature distribution on numerical resolution and dissipative mechanism is investigated. An inert material (with the constitutive properties of HMX) is used to better focus on the mechanics of pore collapse. Two important findings result from this study. First, insufficient resolution can significantly overpredict the hot-spot mass. Second, up to moderate piston velocities (< 1 km/s), shock dissipation alone does not generate sufficient hot-spot mass for initiation. Two other dissipative mechanisms investigated are plastic work and viscous heating. In the cases studied, the integrated temperature distribution has a power-law tail with exponent related to a parameter with dimensions of viscosity. The parameter of either dissipative mechanism can be fit to obtain the hot-spot mass needed for initiation of any single experiment. However, the dissipative mechanisms scale differently with shock strength and pore size. Consequently, to predict initiation behavior over a range of stimuli and as the micro-structure properties of a PBX are varied, sufficient numerical resolution and the correct physical dissipative mechanism are essential. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Menikoff, R (reprint author), Los Alamos Natl Lab, Div Theoret, MS-B214, Los Alamos, NM 87545 USA. EM rtm@lanl.gov NR 10 TC 21 Z9 21 U1 2 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 393 EP 396 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000089 ER PT S AU Nichols, AL Tarver, CM McGuire, EM AF Nichols, AL Tarver, CM McGuire, EM BE Furnish, MD Gupta, YM Forbes, JW TI ALE3D statistical hot spot model results for LX-17 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SOLID EXPLOSIVES AB The Statistical Hot Spot shock initiation and detonation reactive flow model for solid explosives in the ALE3D hydrodynamic computer code provides physically realistic descriptions of. hot spot formation; ignition (or failure to ignite); growth of reaction (or failure to grow) into surrounding particles; coalescence of reacting hot spots; transition to detonation; and self-sustaining detonation. The model has already successfully modeled several processes in HMX-based explosives, such as shock desensitization, that can not predicted by other reactive flow models. In this paper, the Statistical Hot Spot model is applied to experimental shock initiation data on the insensitive triaminotrintrobenzene (TATB) based explosive LX17. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Nichols, AL (reprint author), Lawrence Livermore Natl Lab, POB 808,L-282, Livermore, CA 94551 USA. EM alnichols@llnl.gov; tarver1@llnl.gov NR 14 TC 3 Z9 3 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 397 EP 400 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000090 ER PT S AU Reaugh, JE AF Reaugh, JE BE Furnish, MD Gupta, YM Forbes, JW TI Computer simulations to study the high-pressure deflagration of HMX SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID PROPAGATION AB The accepted micro-mechanical picture of the build-up of detonation in solid explosives from a shock is that imperfections are a source of hot spots. The hot spots ignite and link up in the reaction zone by high-pressure deflagration. Although the deflagration is subsonic, there are so many ignition sites that the pressure build-up is rapid enough to strengthen the initial shock. Quantitative advances in this research require a detailed understanding of deflagration at the high pressure, 1 to 50 GPa, which is present in the reaction zone. We performed direct numerical simulations of highpressure deflagrations using a simplified global (3-reaction) chemical kinetics scheme. We used ALE3D to calculate coupled chemical reactions, heat transfer, and hydrodynamic flow for finite-difference zones comprising a mixture of reactants and products at pressure and temperature equilibrium. The speed of isobaric deflagrations depends on the pressure and initial temperature. We show how this dependence changes with kinetic parameters, including the order of the last reaction step and the heat of formation of the species formed, relative to the reactant. C1 Lawrence Livermore Natl Lab, HE & Organ Grp, Livermore, CA 94551 USA. RP Reaugh, JE (reprint author), Lawrence Livermore Natl Lab, HE & Organ Grp, Livermore, CA 94551 USA. EM jreaugh@llnl.gov NR 15 TC 1 Z9 2 U1 1 U2 7 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 401 EP 404 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000091 ER PT S AU Shaw, MS AF Shaw, MS BE Furnish, MD Gupta, YM Forbes, JW TI Direct simulation of detonation products equation of state SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID ENSEMBLE AB Theoretical calculations are made for the equilibrium detonation products equation of state using a Composite Monte Carlo method. In this study the method is extended to include small (similar to2nm) diamond clusters and to allow for surface chemistry of the groups that cap dangling bonds. An analytic representation of the Gibbs free energy of the cluster as a function of surface composition is incorporated in a fashion similar to that used for internal degrees of freedom for molecules. Bulk carbon phases are incorporated as analytic terms while the molecular fluid mixture is explicitly included in the Monte Carlo simulation. Starting from a very general partition function, equilibrium chemical composition results from a correlated interchange of atoms between species, whether fluid, bulk, cluster, or cluster surface group. Also allowed is fluid-fluid phase separation from terms that reduce to the Gibbs ensemble as a special case. Hugoniots and detonation velocities are determined from interpolation of tabulated equation of state results. Quantum calculations are in progress to better characterize the diamond clusters, surface groups, and their interactions with the molecular fluid. C1 Los Alamos Natl Lab, Grp T14, Los Alamos, NM 87545 USA. RP Shaw, MS (reprint author), Los Alamos Natl Lab, Grp T14, MS B214, Los Alamos, NM 87545 USA. NR 6 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 409 EP 412 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000093 ER PT S AU Valone, SM AF Valone, SM BE Furnish, MD Gupta, YM Forbes, JW TI Particle-velocity dependent rate constants from transition-state theory SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID PENTAERYTHRITOL TETRANITRATE; CHEMICAL-REACTIONS; DETONATION-WAVES; CRYSTAL AB Shock loading activates complex kinetic processes, including detonations, deformations, fracture, spall, and phase transformations. Many practical rate models have succeeded as fitting forms; they have limited predictive capabilities. One route to greater predictability may be to revise contemporary theories of activated rate processes to depend explicitly on properties of the shock environment. The rate model presented here depends on the projection of the particle velocity along a reaction coordinate (or order parameter or slip system depending on the context) describing the transformation process. The model is able to fit both thermal- and shock-activated PETN and nitromethane (NM) barriers in a physically sensible way. The model behaves qualitatively correctly to account for the difference in two NM shock experiments. The model predicis hypersensitivity to dispersion in the particle velocity distribution as it projects onto a reaction coordinate. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Valone, SM (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. EM smv@lanl.gov NR 17 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 417 EP 420 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000095 ER PT S AU Yao, J AF Yao, J BE Furnish, MD Gupta, YM Forbes, JW TI A fast three-dimensional lighting time algorithm SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A narrow band level-set method to calculate the physical lighting time in three dimensions has been implemented with arbitrary hexahedral element systems. This method does not involve finite difference calculation of spatial derivatives. Mesh regularity, and the local topologic equivalence to a regular mesh are not required. The lighting surface is represented by a collection of curved facets contained in partially burnt cells. Level-set functions are calculated by direct measurement of distance to the lighting surface, and are carried only for nodes of a set of elements in a narrow band that covers the lighting surface. In the case of a concave boundary, the nodal distances are calculated with geodesics. A polynomial fitting of nodal level-set values across elements provides third-order spatial accuracy where the surface is sufficiently smooth. The DSD (Detonation Shock Dynamics) level-set equation is integrated directly in the normal direction. The new algorithm is self-initialized and allows easy boundary treatment with body fitting meshes. C1 Lawrence Livermore Natl Lab, Sci Div B, Livermore, CA 94550 USA. RP Yao, J (reprint author), Lawrence Livermore Natl Lab, Sci Div B, Livermore, CA 94550 USA. EM yoh1@llnl.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 421 EP 424 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000096 ER PT S AU Yoh, JJ McClelland, MA AF Yoh, JJ McClelland, MA BE Furnish, MD Gupta, YM Forbes, JW TI Simulating the thermal response of high explosives on time scales of days to microseconds SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We present an overview of computational techniques for simulating the thermal cookoff of high explosives using a multi-physics hydrodynamics code, ALE3D. Recent improvements to the code have aided our computational capability in modeling the response of energetic materials systems exposed to extreme thermal environments, such as fires. We consider an idealized model process for a confined explosive involving the transition from slow heating to rapid deflagration in which the time scale changes from days to hundreds of microseconds. The heating stage involves thermal expansion and decomposition according to an Arrhenius kinetics model while a pressure-dependent bum model is employed during the explosive phase. We describe and demonstrate the numerical strategies employed to make the transition from slow to fast dynamics. C1 Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94551 USA. RP Yoh, JJ (reprint author), Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94551 USA. EM yoh1@llnl.gov; mcclelland1@llnl.gov NR 7 TC 2 Z9 3 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 425 EP 428 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000097 ER PT S AU Clements, BE Mas, EM Maudlin, PJ AF Clements, BE Mas, EM Maudlin, PJ BE Furnish, MD Gupta, YM Forbes, JW TI Developments toward a continuum-level nonspherical void growth model using a micro-mechanics basis SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A phenomenological damage model, based on a successful theory of Continuum Damage Mechanics (CDM), has been investigated for the goal of developing a predictive non-spherical void growth model. Using Green's functions, validated against standard Eshelby analysis, which provides reliable solutions for the growth of non-spherical voids, we attempt to verify several common assumptions of CDM. Non-spherical void growth has been observed in various steels for which we use HY-100 steel as our test system. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Clements, BE (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. EM mas@lanl.gov NR 9 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 443 EP 446 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000101 ER PT S AU Dienes, JK Middleditch, J Zuo, QH Kershner, JD AF Dienes, JK Middleditch, J Zuo, QH Kershner, JD BE Furnish, MD Gupta, YM Forbes, JW TI On the role of crack orientation in brittle failure SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SHEAR CRACKS AB Many materials contain a large number of microcracks that can propagate under sufficiently high stress, but their stability is sensitive to crack orientation. We have explored this sensitivity using classical fracture mechanics with the added feature that interfacial friction is accounted for in the behavior of compression cracks. Our analysis shows that four types of unstable crack growth are possible for a penny-shaped crack under a general state of stress, depending on crack orientation: opening without shear, mixed opening and shear, pure shear without friction, and shear with interfacial friction. In addition, interfacial friction prevents crack growth at all stress intensities in a certain range of compressive stress. It will be shown that these analytic results are captured by the SCRAM brittle-failure algorithm, and that friction strongly affects the orientation of the most unstable shear crack as well as the range of unstable orientations. A second study examines the variations in material response as a function of the number of orientations represented. This is done by computing the dynamic response of an axisymmetric thick ring to internal pressure. With the traditional 9 crack orientations the fluctuation in porosity is about 28%, while with 480 orientations the fluctuation drops to just over 2%. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dienes, JK (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM jkd@lanl.gov NR 15 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 447 EP 450 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000102 ER PT S AU Gray, GT Bourne, NK Millett, JCF Lopez, MF AF Gray, GT Bourne, NK Millett, JCF Lopez, MF BE Furnish, MD Gupta, YM Forbes, JW TI Influence of shock-wave profile shape ("Taylor-wave" versus square-topped) on the shock-hardening and spallation response of 316L stainless steel SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID FRACTURE AB While much has been learned over the past five decades concerning. Shock hardening and the spallation response of materials shock-loaded using "square-topped" shock profiles, achieved via flyer plate loading, considerably less quantitative information is known concerning direct in-contact HE-driven or triangular-wave loading profile shock prestraining on metals and alloys. In this paper the influence of shock-wave profile, using both "square-topped" and triangular-wave pulses, on the shock hardening and spallation response of 316L stainless steel is presented. The shock hardening in 316L SS, using a triangular-shaped pulse and square-topped pulse (pulse duration of 0.75 musec) to a peak shock pressure of 6.6 GPa was found to be reasonably similar. Square-wave loading at 6.6 GPa is observed to result in incipient spallation in 316L SS while triangular-wave loading to an equivalent peak stress is quantified to exhibit no wave-profile "pull-back" nor damage evolution. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gray, GT (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM rusty@lanl.gov; n.k.bourne@rmcs.cranfield.ac.uk; j.millett@rmcs.cranfield.ac.uk NR 6 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 461 EP 464 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000105 ER PT S AU Hixson, RS Gray, GT Rigg, PA Addessio, LB Yablinsky, CA AF Hixson, RS Gray, GT Rigg, PA Addessio, LB Yablinsky, CA BE Furnish, MD Gupta, YM Forbes, JW TI Dynamic damage investigations using triangular waves SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SPALLATION; SOLIDS AB Many experimental investigations of dynamic damage (spall) have been done using gun-driven flat top shock waves to generate release waves that interact and cause tension. Such localized tensile pulses can cause damage to occur, and may cause the target to separate into two pieces. Metals that are subjected to shock loading as a result of being in contact with a detonating high explosive are well known to exhibit a triangular ('Taylor-wave') loading/unloading profile. When such a triangular wave reaches a free surface the lead shock is reflected as a release, interacts with the Taylor wave, and causes a tensile wave of increasing negative amplitude to propagate back into the sample. We describe here new experiments done to investigate the damage process for both flat top and triangular wave dynamic damage experiments. Both time-resolved free surface velocity results and post-experiment metallurgical examination of copper samples are described. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hixson, RS (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM rusty@lanl.gov; prigg@lanl.gov NR 9 TC 10 Z9 10 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 469 EP 472 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000107 ER PT S AU Holtkamp, DB Clark, DA Crain, MA Furnish, MD Gallegos, CH Garcia, IA Hammon, DL Hemsing, WF Shinas, MA Thomas, KA AF Holtkamp, DB Clark, DA Crain, MA Furnish, MD Gallegos, CH Garcia, IA Hammon, DL Hemsing, WF Shinas, MA Thomas, KA BE Furnish, MD Gupta, YM Forbes, JW TI Development of a non-radiographic spall and damage diagnostic SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A new, non-radiographic diagnostic has been developed that appears to provide information on multiple spall and damage layers in metals. The velocities of multiple layers (up to 5 in copper) can be determined using this method, with additional information possible on damaged material between layers at densities less than the bulk metal value. Metals that are melted on release (tin) also seem to exhibit a distinctive signature that is quite different from conventional multi-layer spall. Experimental results on these metals and proton radiographs confirming these results are also presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Holtkamp, DB (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM holtkamp@lanl.gov; mdfumi@sandia.gov; mdfumi@sandia.gov NR 12 TC 12 Z9 14 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 473 EP 476 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000108 ER PT S AU Holtkamp, DB Clark, AA Ferm, EN Gallegos, RA Hammon, D Hemsing, WF Hogan, GE Holmes, VH King, NSP Liljestrand, R Lopez, RP Merrill, FE Morris, CL Morley, KB Murray, MM Pazuchanics, PD Prestridge, KP Quintana, JP Saunders, A Schafer, T Shinas, MA Stacy, HL AF Holtkamp, DB Clark, AA Ferm, EN Gallegos, RA Hammon, D Hemsing, WF Hogan, GE Holmes, VH King, NSP Liljestrand, R Lopez, RP Merrill, FE Morris, CL Morley, KB Murray, MM Pazuchanics, PD Prestridge, KP Quintana, JP Saunders, A Schafer, T Shinas, MA Stacy, HL BE Furnish, MD Gupta, YM Forbes, JW TI A survey of high explosive-induced damage and spall in selected metals using proton radiography SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Multiple spall and damage layers can be created in metal when the free surface reflects a Taylor wave generated by high explosives. These phenomena have been explored in different thicknesses of several metals (tantalum, copper, 6061 T6-aluminum, and tin) using high-energy proton radiography. Multiple images (up to 21) can be produced of the dynamic evolution of damaged material on the microsecond time scale with a <50 ns "shutter" time. Movies and multiframe still images of areal and (Abel inverted) volume densities are presented. An example of material that is likely melted on release (tin) is also presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Holtkamp, DB (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Prestridge, Kathy/C-1137-2012 OI Prestridge, Kathy/0000-0003-2425-5086 NR 5 TC 21 Z9 26 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 477 EP 482 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000109 ER PT S AU McCluskey, CW Wilke, MD Anderson, WW Byers, ME Holtkamp, DB Rigg, PA Furnish, MD Romero, VT AF McCluskey, CW Wilke, MD Anderson, WW Byers, ME Holtkamp, DB Rigg, PA Furnish, MD Romero, VT BE Furnish, MD Gupta, YM Forbes, JW TI Discrete layer verification of the LiF window spall diagnostic SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Recently, LiF windows suspended close to the surface have been employed as a non-radiographic spall diagnostic. Calibration has typically used HE to shock metals to produce spall layers. Because the exact characteristics of these layers cannot be pre-determined, we are using a gas gun to test the accuracy and repeatability of the diagnostic. We impact a LiF or PMMA window in front of a VISAR probe with a projectile consisting of four thin stainless steel disks spaced apart 200 microns with either vacuum or polyethylene. The measured signature from the VISAR probe is compared with what is expected from the layered assembly traveling at the projectile's velocity. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP McCluskey, CW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM craigm@lanl.gov; wilke@lanl.gov; muander@sandia.gov; holtkamp@lanl.gov; prigg@lanl.gov; mdfumi@sandia.gov; mdfumi@sandia.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 483 EP 486 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000110 ER PT S AU Thissell, WR Henrie, BL Cerreta, EK Anderson, WA Atchison, WL Cochrane, CC Kaul, AM Keinigs, RK Ladish, JS Lindemuth, IR Oro, DM Paisley, D Reinovsky, R Rodriguez, G Salazar, MA Stokes, JL Taylor, AJ Tonks, DL Zurek, AK AF Thissell, WR Henrie, BL Cerreta, EK Anderson, WA Atchison, WL Cochrane, CC Kaul, AM Keinigs, RK Ladish, JS Lindemuth, IR Oro, DM Paisley, D Reinovsky, R Rodriguez, G Salazar, MA Stokes, JL Taylor, AJ Tonks, DL Zurek, AK BE Furnish, MD Gupta, YM Forbes, JW TI Metallurgical characterization of atlas cylindrically convergent spallation experiments SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The microstructural distribution and nature of damage from three different cylindrically convergent spallation experiments performed on the pulsed power machine named Atlas are presented. Longitudinal momentum trapping was used to minimize the influence of release waves and thereby decrease the dimensionality of the experiments. Two of the experiments involved soft capture of the spalled piece. The material used is a proprietary directionally cast Al alloy with a mostly equiaxed grain morphology and essentially random texture in the region of spallation. The damage was most distributed in the lowest impact velocity shot and became progressively more narrow with increasing impact velocity. The effectiveness of the momentum trap design increased with increasing impact velocity. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Thissell, WR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 2 TC 1 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 499 EP 502 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000114 ER PT S AU Thompson, DG Wright, WJ AF Thompson, DG Wright, WJ BE Furnish, MD Gupta, YM Forbes, JW TI Mechanical properties from PBX 9501 pressing study SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A PBX 9501 pressing study was conducted by researchers in ESA-WMM, LANL, to identify the hydrostatic pressing parameters most important in fabricating high-density parts with uniform density. In this study, 31 charges were pressed using a full permutation of six pressing parameters. Five charges from the set of 31 were selected for an evaluation of their mechanical properties, specifically uniaxial compression and tension. Charges were selected to 1) span the density range of the study, and 2) allow two direct comparisons of pressing parameters independent of bulk density (density has a well-established affect on some material properties). Three PBX 9501 charges pressed isostatically at Pantex Plant in Amarillo, TX were also included in the study. The tensile properties of the 8 charges varied significantly. Careful evaluation of the results suggests that an increase in pressing temperature may correlate with an increase in tensile stress (strength) and a decrease in strain (ductility). Trends in compression exist but are less pronounced. In an effort to explore the relationship between pressing temperature and tensile strength, four sheets of Estane polymer (a component of the PBX 9501 binder) were compression molded at 70, 90, 110 and 130degreesC. The tensile strength of Estane was observed to increase by a factor of nearly 20 when the molding temperature was increased from 70 to 90degreesC (strength increase was negligible beyond 90degreesC). We present an outline of ongoing work that will irrefutably quantify the mechanical property affects of both pressing temperature and dwell time on PBX 9501. C1 Los Alamos Natl Lab, DX2, Los Alamos, NM 87545 USA. RP Thompson, DG (reprint author), Los Alamos Natl Lab, DX2, POB 1663, Los Alamos, NM 87545 USA. EM dkgraff@lanl.gov; mark.w.wright@awe.co.uk NR 4 TC 1 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 503 EP 506 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000115 ER PT S AU Tonks, DL Thissell, WR Schwartz, AS AF Tonks, DL Thissell, WR Schwartz, AS BE Furnish, MD Gupta, YM Forbes, JW TI Modeling incipient copper damage data from the tensile Hopkinson bar and gas gun SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Ductile damage in copper has been created using a split tensile Hopkinson pressure bar. Precise momentum trapping has made it possible to arrest the damage after a short tensile pulse before complete fracture. This process has been modeled with a void nucleation and growth law. 2D calculations have been performed to compare with final porosity and void number density data. The tensile bar damage modeling has been supplemented with modeling of incipient spallation of copper in a plate impact gas gun experiment. These two experiments differ widely in the (negative) pressure level and modeling both their porosity results will pen-nit the creation of a nucleation model that spans the resulting wide pressure range. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tonks, DL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM tonks@lanl.gov; thissell@lanl.gov NR 4 TC 1 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 507 EP 510 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000116 ER PT S AU Baer, MR Trott, WM AF Baer, MR Trott, WM BE Furnish, MD Gupta, YM Forbes, JW TI Mesoscale studies of shock loaded tin sphere lattices SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The shock response of heterogeneous materials involves highly fluctuating states and localization effects that are produced by mesostructure. Prior studies have examined this shock behavior in randomized inert and reactive media. In this work, we investigate the shock behavior in a porous lattice consisting of hexagonally packed layers of 500 mum tin spheres impacted at 0.5 km/s. This ordered geometry provides a well-defined configuration to validate mesoscale material modeling based on three-dimensional CTH calculations. Detailed wave fields are experimentally probed using a line-imaging interferometer and transmitted particle velocities are compared to numerical mesoscale. calculations. Multiple shock fronts traverse the porous layers whereby particle-to-particle interactions cause stress bridging effects and the evolution of organized wave structures. C1 Sandia Natl Labs, Engn Sci Ctr 9100, Albuquerque, NM 87185 USA. RP Baer, MR (reprint author), Sandia Natl Labs, Engn Sci Ctr 9100, POB 5800, Albuquerque, NM 87185 USA. EM baer4@llnl.gov NR 7 TC 4 Z9 4 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 517 EP 520 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000118 ER PT S AU Blumenthal, WR Brown, DW Tome, CN AF Blumenthal, WR Brown, DW Tome, CN BE Furnish, MD Gupta, YM Forbes, JW TI Evolution of crystallographic texture and strength in beryllium SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The evolution of the dynamic mechanical behavior and crystallographic texture in polycrystalline beryllium with different initial textures was measured and compared to a polycrystalline plasticity model. The split-Hopkinson pressure bar compression behavior and the activity of deformation mechanisms were found to be highly dependent on the initial texture and the loading orientation. Neutron diffraction measurements of the bulk texture as a function of strain were made at the Manuel Lujan Jr. Neutron Scattering Center. The activation of deformation twinning at high strain rates in beryllium was observed to cause both anisotropy in the mechanical behavior and rapid evolution of the texture compared to slip deformation alone. A visco-plastic self-consistent (VPSC) polycrystalline plasticity model was used to closely simulate the texture and flow strength evolution by accounting for contributions from both slip deformation and twinning mechanisms. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Blumenthal, WR (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA. EM blumenthal@lanl.gov; jlbrown@sandia.gov NR 6 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 525 EP 528 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000120 ER PT S AU Burkett, MW Clancy, SP Maudlin, PJ Holian, KS AF Burkett, MW Clancy, SP Maudlin, PJ Holian, KS BE Furnish, MD Gupta, YM Forbes, JW TI Coupled plasticity and damage modeling and their applications in a three-dimensional eulerian hydrocode SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID ANISOTROPIC PLASTICITY; DEFORMATION AB Previously developed constitutive models and solution algorithms for continuum-level anisotropic elastoplastic material strength and an isotropic damage model TEPLA have been implemented in the three-dimensional Eulerian hydrodynamics code known as CONEJO. The anisotropic constitutive modeling is posed in an unrotated material frame of reference using the theorem of polar decomposition to compute rigid-body rotation. TEPLA is based upon the Gurson flow surface (a potential function used in conjunction with the associated flow law). The original TEPLA equation set has been extended to include anisotropic elastoplasticity and has been recast into a new implicit solution algorithm based upon an eigenvalue scheme to accommodate the anisotropy. This algorithm solves a two-by-two system of nonlinear equations using a Newton-Raphson iteration scheme. Simulations of a shaped-charge jet fort-nation, a Taylor cylinder impact, and an explosively loaded hemishell were selected to demonstrate the utility of this modeling capability. The predicted deformation topology, plastic strain, and porosity distributions are shown for the three simulations. C1 Los Alamos Natl Lab, Div Appl Phys, Primary Design & Assessment Grp, MST 086, Los Alamos, NM 87545 USA. RP Burkett, MW (reprint author), Los Alamos Natl Lab, Div Appl Phys, Primary Design & Assessment Grp, MST 086, POB 1663, Los Alamos, NM 87545 USA. EM mwb@lanl.gov; blh@lanl.gov NR 10 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 529 EP 532 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000121 ER PT S AU Cerreta, E Gray, GT Henrie, BL Brown, DW Hixson, RS Rigg, PA AF Cerreta, E Gray, GT Henrie, BL Brown, DW Hixson, RS Rigg, PA BE Furnish, MD Gupta, YM Forbes, JW TI The influence of peak stress on the mechanical behavior and the substructural evolution in shock-prestrained zirconium SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID CRYSTALLOGRAPHIC ASPECTS; ALPHA->OMEGA TRANSITION; LOADED ZIRCONIUM; PHASE; TEMPERATURE; METAL AB The post shock mechanical behavior and substructure evolution of zirconium (Zr) under shock prestrained at 5.8 and 8 GPa, above and below the pressure induced alpha-omega phase transition, has been quantified. The reload yield stress of Zr shock prestrained to 8 GPa was found to exhibit enhanced shock hardening when compared to the flow stress measured quasi-statically at an equivalent strain. In contrast, the reload yield behavior of Zr specimens shocked to 5.8 GPa did not exhibit enhanced shock hardening. The microstructure of the as-annealed and shock prestrained materials were examined. The presence of a reduced available glide distance due to a relatively more well developed dislocation Substructure and increased twinning over quasi-static specimens deformed to comparable strains correlates with the increased yield stresses after shock prestraining at 8 GPa. Additionally, the retention of similar to 40% by volume metastable high-pressure omega-phase in specimens shocked to 8 GPa and its absence in the 5.8 GPa specimen, is thought to contribute to the increased yield stress in the 8 GPa specimens. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cerreta, E (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM ecerreta@lanl.gov; rusty@lanl.gov; prigg@lanl.gov NR 16 TC 2 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 541 EP 544 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000124 ER PT S AU Crawford, P Rainey, K Rightley, P Hammerberg, JE AF Crawford, P Rainey, K Rightley, P Hammerberg, JE BE Furnish, MD Gupta, YM Forbes, JW TI A novel experimental technique for the study of high-speed friction under elastic loading conditions SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SOLIDS AB The role of friction in high strain-rate events is not well understood despite being an important constitutive relationship in modem modeling and simulation studies of explosive events. There is a lack of experimental data available for the validation of models of dynamic sliding. The Rotating Barrel Gas Gun (RBGG) is a novel, small-scale experimental facility designed to investigate interfacial dynamics at high loads and sliding speeds. The RBGG utilizes a low-pressure gas gun to propel a rotating annular projectile towards an annular target rod. Upon striking the target, the projectile imparts both an axial and a torsional impulse into the target at a timescale relevant to explosively-driven events. Resulting elastic waves are measured using strain gages attached to the target rod. The coefficient of friction is obtained through an analysis of the resulting strain wave data. Initial experiments have been performed using dry copper/copper interfaces. We find that the measured coefficient of friction can evolve significantly oiler a 30 mus event. C1 Los Alamos Natl Lab, Dynam Expt Div, Los Alamos, NM 87545 USA. RP Crawford, P (reprint author), Los Alamos Natl Lab, Dynam Expt Div, POB 1663, Los Alamos, NM 87545 USA. EM paulac@lanl.gov; rainey@lanl.gov; jeh@lanl.gov NR 4 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 545 EP 548 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000125 ER PT S AU Hackenberg, R Swift, D Bourne, N Gray, G Paisley, D Thoma, D Cooley, J Hauer, A AF Hackenberg, R Swift, D Bourne, N Gray, G Paisley, D Thoma, D Cooley, J Hauer, A BE Furnish, MD Gupta, YM Forbes, JW TI Dynamic properties of nickel-titanium alloys SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID EQUATIONS AB The shock response of near-equiatomic Ni-Ti alloys have been investigated to support studies of shock-induced martensitic transitions. The equation of state (EOS) and elasticity were predicted using ab initio quantum mechanics. Polycrystalline NiTi samples were prepared with a range of compositions, and thickesses between about 100 and 400 mum. Laser-driven flyer impact experiments were used to verify the EOS and to measure the flow stress from the amplitude of the elastic precursor; the spall strength was also obtained from these experiments. The laser flyer EOS data were consistent with Hugoniot points deduced from gas gun experiments. Decaying shocks were induced in samples, by direct laser irradiation with a variety of pressures and durations, to investigate the threshold for martensite formation. C1 Los Alamos Natl Lab, MST 6, Los Alamos, NM 87545 USA. RP Hackenberg, R (reprint author), Los Alamos Natl Lab, MST 6, POB 1663, Los Alamos, NM 87545 USA. EM dswift@lanl.gov; rusty@lanl.gov RI Cooley, Jason/E-4163-2013 NR 8 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 561 EP 564 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000129 ER PT S AU Hammerberg, JE Ravelo, R Germann, TC Kress, JD Holian, BL AF Hammerberg, JE Ravelo, R Germann, TC Kress, JD Holian, BL BE Furnish, MD Gupta, YM Forbes, JW TI Sliding friction at compressed Ta/Al interfaces SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID MOLECULAR-DYNAMICS; METALS; PSEUDOPOTENTIALS; TRANSITION; HYDROGEN; DEFECTS; TA AB The physics of sliding at compressed Ta/Al interfaces is discussed based upon the results of large scale 3D NEDM simulations. A new set of Embedded Atom Method potentials has been constructed to treat the Ta-Al interaction. Pressures of order 15 GPa are studied and the velocity dependence of the frictional force is studied for several interfacial configurations including Al(100)/Ta(100) and Al(111)/Ta(110). Generic behavior is observed, characterized by a linear increase at low velocities followed by a power law decrease at high velocities associated with near interface structural transformation in Al. C1 Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA. RP Hammerberg, JE (reprint author), Los Alamos Natl Lab, Div Appl Phys, POB 1663, Los Alamos, NM 87545 USA. EM jeh@lanl.gov; ravelo@lanl.gov; tcg@lanl.gov; jdk@lanl.gov; blh@lanl.gov NR 25 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 565 EP 568 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000130 ER PT S AU Harstad, EN Maudlin, PJ McKirgan, JB AF Harstad, EN Maudlin, PJ McKirgan, JB BE Furnish, MD Gupta, YM Forbes, JW TI Anisotropic failure modeling for HY-100 steel SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID STRESS STATE; STRAIN AB HY-100 steel is a material that behaves isotropically in the elastic and plastic region and acts anisotropically in failure. Since HY-100 is a ductile metal, a more gradual failure process is observed as opposed to the nearly instantaneous failure in brittle materials. We extend our clasto-plastic-damage constitutive model by including of a decohesion model to describe material behavior between the onset of failure and fracture. We also develop an anisotropic failure surface to account for directionality in material failure. Both the anisotropic failure and decohesion models have been implemented into a finite element code, where the effects of these models are studied in a uniaxial stress simulations, a plate impact simulations, and a quasistatic notched round bar tensile test simulations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Harstad, EN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM enh@lanl.gov NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 569 EP 572 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000131 ER PT S AU Hayes, DB Gray, GT Hixson, RS Zurek, AK Vorthman, JE Anderson, WW AF Hayes, DB Gray, GT Hixson, RS Zurek, AK Vorthman, JE Anderson, WW BE Furnish, MD Gupta, YM Forbes, JW TI Precursor suppression by shear stress relaxation in U-Nb(6-wt%) SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB U-Nb(6-wt%) exhibits plastic yield strength of a few-tenths of a GPa that can vary depending upon the starting microstructure and heat-treatment. However, when a several-mm thick specimen of U-Nb(6-wt%) is shock loaded in the range between 1.5 and 10 GPa, no elastic precursor is observed in interferometer measurements at the rear free surface. The absence of the elastic precursor and other features of the compression and release measurements are explained by assuming shear stress-relaxation rate is dependent upon the shear stress. The resulting stress waves are unsteady and broaden so that shear stress relaxation can occur in the front preventing the plastic yield point from being reached. U-Nb(6-wt%) is known to twin in quasi-static compression and shear-induced, rate-dependent twinning is likely the underlying cause for shear stress relaxation in our experiments. Recent experiments in which U-Nb(6-wt%) was heavily cold-rolled ( work-hardening to similar to25% strain) display no evidence of a precursor, admitting the possibility of a pressure or temperature induced stress-relaxation process. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hayes, DB (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM dennis@nmia.com; rusty@lanl.gov; hixson@lanl.gov; zurek@lanl.gov NR 6 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 573 EP 576 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000132 ER PT S AU McClellan, KJ Swift, DC Paisley, DL Koskelo, AC AF McClellan, KJ Swift, DC Paisley, DL Koskelo, AC BE Furnish, MD Gupta, YM Forbes, JW TI Dynamic properties of nickel-aluminum alloy SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID EQUATIONS AB We are investigating interactions between shocks and grain boundaries in the anisotropic alloy NiAl; as part of this work, we need to know the shock response of single crystals. The equation of state (EOS) and elasticity were predicted using ab initio quantum mechanics. NiAl crystals were obtained from GE, and also prepared locally, and cut to thickesses between about 100 and 500 microns. Laser-driven flyer impact experiments were used to verify the EOS and to measure the elastic precursor wave as a function of crystal orientation. Shocks induced by direct laser irradiation were used to investigate the elastic precursor and to demonstrate that the imaging VISAR system had a temporal resolution adequate to distinguish between different orientations. A single-crystal plasticity model is under development to design and interpret experiments on bicrystals. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP McClellan, KJ (reprint author), Los Alamos Natl Lab, MST-8, Los Alamos, NM 87545 USA. EM mcclellandl@llnl.govH.gov; dswift@lanl.gov; koskelo@lanl.gov NR 4 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 593 EP 596 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000137 ER PT S AU Vogler, TJ Asay, JR AF Vogler, TJ Asay, JR BE Furnish, MD Gupta, YM Forbes, JW TI A distributional model for elastic-plastic behavior of shock-loaded materials SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB To address known shortcomings of classical metal plasticity for describing material behavior under shock loading, a model which incorporates a distribution in the deviatoric stress state is developed. This distribution will translate in stress space under loading, and growth of the distribution can be included in the model as well. This proposed model is capable of duplicating the key features of a set of reshock and release experiments on 6061-T6 aluminum, many of which are not captured by classical plasticity. The model is relatively simple, is only moderately more computationally intensive, and requires few additional material parameters. C1 Sandia Natl Labs, Solid Dynam & Energet Mat Dept, Albuquerque, NM 87185 USA. RP Vogler, TJ (reprint author), Sandia Natl Labs, Solid Dynam & Energet Mat Dept, POB 5800, Albuquerque, NM 87185 USA. EM tjvogle@sandia.gov; jrasay@wsu.edu RI Vogler, Tracy/B-4489-2009 NR 6 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 617 EP 620 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000143 ER PT S AU Xue, Q Gray, GT Chen, SR AF Xue, Q Gray, GT Chen, SR BE Furnish, MD Gupta, YM Forbes, JW TI Influence of shock prestraining on shear localization in 316L stainless steel SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The effect of "Taylor-Wave" shock prestraining on the adiabatic shear localization response of annealed and shock pre-shocked 316L stainless steel (316L SS) was investigated. A forced shear technique using "hat-shaped" specimens on a compression split-Hopkinson bar was utilized. The mechanical responses at two different strain rates showed that the shock pre-strained specimens exhibit Much higher yield stresses but much lower strain hardening effects than those in the annealed steel. The dynamic shear responses indicate that the shear stress in the shock pre-strained steel arrived at the instable point at Much smaller plastic strain than the annealed steel. The initial microstructures in these two materials exhibit significant differences of textures and defects that may dominate the initiation of shear bands. The pre-shocked steel, which contains more deformation twins, was found to display a higher propensity to trigger localized deformation than the annealed steel. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Xue, Q (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MST-8,MS G755, Los Alamos, NM 87545 USA. EM qxue@lanl.gov; rusty@lanl.gov NR 8 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 633 EP 636 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000147 ER PT S AU Young, JA Wirth, BD AF Young, JA Wirth, BD BE Furnish, MD Gupta, YM Forbes, JW TI The interaction of dislocations and radiation-induced obstacles at high-strain rate SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Improved understanding of the plastic deformation of metals during high strain rate shock loading is key to predicting their resulting material properties. This paper presents the results of molecular dynamics simulations that identify the deformation modes of aluminum over a range of applied shear stresses and examines the interaction between dislocations and irradiation induced obstacles. These simulations show that while super-sonic dislocation motion can occur during impact loading, the finite dimensions of the materials render this motion transient. Larger applied loads do not stabilize supersonic dislocations, but instead lead an alternate deformation mode, namely twinning. Finally, the atomistic mechanisms that underlie the observed changes in the mechanical properties of metals as a function of irradiation are examined. Specifically, simulations of the interactions between moving edge dislocations and nanometer-sized helium bubbles provide insight into increases of the critical shear stresses but also reveal the effect of internal gas pressure on the deformation mode. The information gained in these studies provides fundamental insight into materials behavior, as well as important inputs for multi-scale models of materials deformation. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Young, JA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM jyoung@llnl.gov RI Wirth, Brian/O-4878-2015 OI Wirth, Brian/0000-0002-0395-0285 NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 637 EP 640 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000148 ER PT S AU Alcon, RR Robbins, DL Sheffield, SA Stahl, DB Fritz, JN AF Alcon, RR Robbins, DL Sheffield, SA Stahl, DB Fritz, JN BE Furnish, MD Gupta, YM Forbes, JW TI Shock compression of silicon polymer foams with a range of initial densities SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We report here on a collection of shock compression experiments on a silicon polymer foam with varying degrees of distension from low (similar to0.4 g/cm(3)) to the near fully dense material (similar to 1 g/cm 3). These experiments are being carried out on a two-stage gas-gun (50 mm bore) with a Kel-F 81 impactor at velocities between 1.5 and 3.1 km/s. Particle and shock velocity measurements are made with magnetic gauges by inserting the gauge package (0.001 inches thick) between layers of 2.3 mm thick foam. Special attention is required for assembly of these targets due to the foam's low strength. To minimize compression and gaps at interfaces, the foams are positioned between support rings, which are machined to match the foam's thickness. The Hugoniot data from these experiments is compared to unpublished data obtained with explosively driven flyers at Los Alamos National Laboratory in the early 1980's. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Alcon, RR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM robbins@awe.co.uk; ssheffield@lanl.gov NR 2 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 651 EP 654 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000151 ER PT S AU Rae, PJ Gray, GT Dattelbaum, DM Bourne, NK AF Rae, PJ Gray, GT Dattelbaum, DM Bourne, NK BE Furnish, MD Gupta, YM Forbes, JW TI The Taylor impact response of PTFE (teflon) SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID POLYTETRAFLUOROETHYLENE AB Whilst Polytetrafluoroethylene (PTFE) is an unusually ductile polymer, it undergoes an abrupt ductile-brittle transition at modest impact velocities. No previous explanation for this behaviour seems to have been presented. In this paper we examine the role of a pressure-induced phase transition in PTFE in the failure of Taylor cylinder samples. Whilst a phase transition occurs at approximately 0.65 GPa at 21degreesC, the transition pressure is inversely related to temperature. Varying the temperature of the, fired Taylor cylinders shows that the phase transition is likely to be involved because the critical velocity increased for decreasing temperature, despite the material fracture toughness decreasing. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rae, PJ (reprint author), Los Alamos Natl Lab, MST-8,MS-G755, Los Alamos, NM 87545 USA. EM prae@lanl.gov; rusty@lanl.gov; danadal@lanl.gov; n.k.bourne@rmcs.cranfield.ac.uk NR 11 TC 9 Z9 9 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 671 EP 674 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000156 ER PT S AU Robbins, AL Sheffield, SA Alcon, RR AF Robbins, AL Sheffield, SA Alcon, RR BE Furnish, MD Gupta, YM Forbes, JW TI Magnetic particle velocity measurements of shocked teflon SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A series of shock compression experiments have been undertaken on Teflon using single- and two-stage gas-guns. Peak pressures in these experiments range from a few kbars to over 10 kbars, as well as one shot completed at 117 kbar. Multiple particle velocity wave profiles, at a number of Langrangian positions, are obtained for each experiment using in-situ magnetic gauges. Shock velocity is calculated from arrival times at both the particle velocity gauges and at embedded shock trackers. These direct measurements of particle and shock velocity are compared to previous shock compression results on Teflon. Particular attention is focused in the region below 10 kbar where evidence of a shock induced phase transition has been reported [1], based upon a cusp in the Hugoniot. The volume change for this transition is only similar to2.2% making its observation difficult. A two-wave structure on the shock front would be strong evidence of the shock-induced transition, but has not been observed in these initial low-pressure experiments. However, the Hugoniot data does show a subtle cusp between two of these shots at pressures of 6.4 and 7.9 kbar. The presence of the cusp is consistent with existing data, but appears at slightly higher pressure. Additionally, the in-situ particle velocity gauges show an evolving wave front, which is likely associated with Teflon's visco-elastic properties. The wave front is initially steep, but rounds significantly after the wave has propagated several millimeters into the target. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Robbins, AL (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM robbins@lanl.gov; ssheffield@lanl.gov NR 6 TC 4 Z9 4 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 675 EP 678 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000157 ER PT S AU Anderson, MU Setchell, RE Cox, DE AF Anderson, MU Setchell, RE Cox, DE BE Furnish, MD Gupta, YM Forbes, JW TI Shock compression and release properties of alumina-filled epoxy SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID PARTICULATE-LOADED MATERIALS; DYNAMICAL RESPONSE; UNFILLED EPOXIES; WAVE; PARTICLES; BEHAVIOR; MATRIX AB Alumina-filled epoxies are used to encapsulate ferroelectric ceramics in shock-driven, pulsed power devices. Device performance is strongly influenced by the shock compression and release properties of the encapsulant, which must be adequately understood in order to develop a capability for numerically simulating the operation of these power sources. In previous studies, Hugoniot states and release velocities were measured in reverse-impact experiments using laser interferometry (VISAR) at stresses up to 5 GPa. In addition, wave profiles were obtained in transmitted-wave experiments at fixed impact conditions as a function of initial temperature. These experiments showed an extended wave structure having a rise time that increased with decreasing temperature. In recent studies, Hugoniot states and release velocities at stresses up to 10 GPa have been obtained in reverse-impact experiments. Transmitted-wave experiments have examined the effects of wave amplitude on the wave structure and also the evolution of this structure with increasing propagation distance. Unsteady wave propagation with strongly viscous behavior is observed over the range of shock conditions examined. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Anderson, MU (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM muander@sandia.gov; resetch@sandia.gov; decox@sandia.gov NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 685 EP 688 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000159 ER PT S AU Mattsson, AE AF Mattsson, AE BE Furnish, MD Gupta, YM Forbes, JW TI Equation of state for a high-density glass SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID FAILURE AB Properties of relevance for the equation of state for a high-density glass are discussed. We review the effects of failure waves, comminuted phase, and compaction on the validity of the Mie-Gruneisen EOS. The specific heat and the Gruneisen parameter at standard conditions for a rho(0) = 5.085 g/cm(3) glass ("Glass A") is then estimated to be 522 mJ/g/K and 0.1 - 0.3, respectively. The latter value is substantially smaller than the value of 2.1751 given in the SESAME tables for a high-density glass with rho(0) = 5.46 g/cm(3) [1]. The present unusual value of the Gruneisen parameter is confirmed from the volume dependence determined from fitting the Mie-Gruneisen EOS to shock data in Ref. [2]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mattsson, AE (reprint author), Sandia Natl Labs, MS 0196, Albuquerque, NM 87185 USA. EM aematts@sandia.gov NR 9 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 743 EP 746 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000173 ER PT S AU Reinhart, WA Chhabildas, LC AF Reinhart, WA Chhabildas, LC BE Furnish, MD Gupta, YM Forbes, JW TI Dynamic strength of AD995 alumina at MBAR stress levels SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB An investigation of the strength of AD995 alumina in the shocked state was assessed over the stress range of 26-120 GPa. Velocity interferometry was used to measure loading, unloading, and reloading profiles from the initial shocked state. These results show that alumina retains considerable strength at stress states exceeding 120 GPa. An important observation, as with some metals, is that there is a substantial increase in strength during reloading and a well-defined elastic behavior is observed. The unloading and reloading technique described also yields data to estimate a dynamic mean stress. C1 Sandia Natl Labs, Dept 1647, Albuquerque, NM 87185 USA. RP Reinhart, WA (reprint author), Sandia Natl Labs, Dept 1647, POB 5800, Albuquerque, NM 87185 USA. EM wdreinh@sandia.gov; lcchhab@sandia.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 759 EP 764 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000177 ER PT S AU Liu, C AF Liu, C BE Furnish, MD Gupta, YM Forbes, JW TI Fracture of the PBX 9501 high explosive SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB In contrast to many brittle solids, crack initiation and propagation in PBX 9501 high explosive and its simulant are preceded by the formation and extension of a sizable bridging zone. In this investigation, fracture experiments on the high-explosive material, PBX 9501, were conducted. From the experimental measurement, we are able to determine quantitatively the stress-bridging law (or decohesion law) that characterizes the relationship between the bridging stress and the opening displacement across the bridging zone. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Liu, C (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM cliu@lanl.gov NR 9 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 786 EP 791 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000183 ER PT S AU Martinez, AR Hooks, DE Dick, JJ AF Martinez, AR Hooks, DE Dick, JJ BE Furnish, MD Gupta, YM Forbes, JW TI Longitudinal and lateral ytterbium gauge measurements in PBX 9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID STRESSES; IMPACT AB Experiments were performed with in-material ytterbium piezoresistive gauges in PBX 9501. Impact stresses were below 2 GPa. Experiments were performed in a few different target geometries, with gauges placed with varying depths, lateral distances, and adhesive environments. The gauge placement in the different geometries resulted in some differences in the data acquired. The most important discrepancies in the data resulted from the use of machined grooves for gauge placement. The variations in experimental design will be presented along with a comparison of the data acquired for these variations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Martinez, AR (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM armartinez@lanl.gov; dhooks@lanl.gov NR 8 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 792 EP 795 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000184 ER PT S AU Peterson, PD Mang, JT Fletcher, MA Olinger, BW Roemer, EL AF Peterson, PD Mang, JT Fletcher, MA Olinger, BW Roemer, EL BE Furnish, MD Gupta, YM Forbes, JW TI Influence of pressing parameters on the microstructure, of PBX 9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SCATTERING AB Microstructural features, such as defects, crystal morphology, and crystal size distribution can dramatically affect the ignition sensitivity, performance, and mechanical properties of energetic materials. While these features can be characterized for the raw material, little is known about how they are altered during pressing. For example, in the preparation of a consolidated charge of PBX 9501, variables such as ultimate pressure, number of pressing cycles, dwell time, or rest time are varied in order to achieve nominal density of 1.830 g/cc. Although this density is met, differences in pressing parameters can lead to variations in microstructure between samples. To evaluate the effect of pressing parameters on the microstructure, three cylinders of PBX 9501 have been pressed at 5 kpsi, 15 kpsi, and 30 kpsi, using a 100 Ton heated steel die press. Polarized light microscopy (PLM) images taken at 144 locations within each cylinder show differences in porosity, crystal size and size distribution between cylinders and at different locations within the same cylinder. Scanning electron microscopy (SEM) further verifies increased fracture and rubblization of HMX during pressing. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Peterson, PD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM pdp@lanl.gov NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 796 EP 799 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000185 ER PT S AU Asay, BW Son, SF Busse, JR Oschwald, DM AF Asay, BW Son, SF Busse, JR Oschwald, DM BE Furnish, MD Gupta, YM Forbes, JW TI Observations on the mechanism of reaction propagation in metastable intermolecular composites SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Metastable Intermolecular Composite (MIC) materials are comprised of a mixture of oxidizer and fuel with particle sizes in the nanometer range. They are a subclass of materials known as thermites. The mechanism responsible for the propagation of reaction in loose compacts is not well understood. We have conducted a series of experiments using high-speed photography and pressure transducers in an attempt to identify the dominant mechanism. We studied a mixture of aluminum and molybdenum trioxide. Of the four possible candidates (radiation, convection, conduction, and acoustic/compaction), these preliminary studies identify convection as the most likely. However, the extent of contribution of the other modes is not yet known and this will receive further study. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Asay, BW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM bwa@lanl.gov NR 5 TC 3 Z9 3 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 827 EP 830 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000192 ER PT S AU Aslam, TD Bdzil, JB Hill, LG AF Aslam, TD Bdzil, JB Hill, LG BE Furnish, MD Gupta, YM Forbes, JW TI Analysis of the LANL detonation-confinement test SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB In general, the confinement of a high explosive (HE) by differing inert materials can change the detonation speed and shock locus. The hydrodynamic basis of this effect can be understood by examining the pressure/streamline-deflection matching condition at the HE/inert interface [1]. A relatively simple shock polar analysis provides a good leading-order prediction of the confinement effect on a propagating detonation. Here, studies of various detonation-inert confinement interactions are examined for PBX 9502. From a theoretical perspective, the appropriate shock polar analysis is carried out for several inerts of interest. It is shown that the phase speed of the shock along the HE/inert interface can play a role in the matching - which isn't the case in the previous analysis for strong shocks in ideal gases [1]. From an experimental perspective, we analyze the results of PBX 9502 sandwich tests [3], where the confining inert is changed from theoretically unconfined (polymethylmethacrylate (PMMA)-plexiglas) to heavily confined (stainless steel (SS 304)). These experimental results are compared to theoretical predictions based on Detonation Shock Dynamics (DSD). C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Aslam, TD (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM aslam@lanl.gov NR 4 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 831 EP 834 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000193 ER PT S AU Ferm, EN Dennison, S Lopez, R Prestridge, K Quintana, JP Espinoza, C Hogan, G King, N Lopez, JD Merrill, F Morley, K Morris, CL Pazuchanics, P Saunders, A Baker, SA Liljestrand, R Thompson, RT AF Ferm, EN Dennison, S Lopez, R Prestridge, K Quintana, JP Espinoza, C Hogan, G King, N Lopez, JD Merrill, F Morley, K Morris, CL Pazuchanics, P Saunders, A Baker, SA Liljestrand, R Thompson, RT BE Furnish, MD Gupta, YM Forbes, JW TI Proton radiography experiments on shocked high explosive products SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We studied the propagation of detonation waves and reflections of normal incident detonation waves in explosive products using the 800 MeV proton radiography facility at LANSCE. Using this system, we obtain seven to twenty-one radiographic images of each experiment. We have examined the experimental wave velocity and density of the materials ahead and behind of the shocks as inferred from radiographs and compare them to standard explosive equations of state. Finally we compare the experiments with calculations of the experiments using the MESA hydrodynamics code. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ferm, EN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM enf@lanl.gov RI Prestridge, Kathy/C-1137-2012 OI Prestridge, Kathy/0000-0003-2425-5086 NR 4 TC 2 Z9 2 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 839 EP 842 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000195 ER PT S AU Hill, LG Aslam, TD AF Hill, LG Aslam, TD BE Furnish, MD Gupta, YM Forbes, JW TI The LANL detonation-confinement test: Prototype development and sample results SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We present the prototype design of a precision "sandwich"-type test, which is optimized for studying the effects of inert confinement on detonation propagation. Design criteria and features are discussed, and sample data is presented for PBX 9502 with 304 stainless steel and PMMA confinement. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hill, LG (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM lgh@lanl.gov NR 4 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 847 EP 850 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000197 ER PT S AU Lee, KY Kennedy, JE Asay, BW Son, SF Martin, ES AF Lee, KY Kennedy, JE Asay, BW Son, SF Martin, ES BE Furnish, MD Gupta, YM Forbes, JW TI Preparation and characterization of fine-particle NTO and its formulation with Al nano-powders SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We have initiated study of the effect of nano-aluminum on the detonation performance of NTO. A novel method for the preparation of both fine-particle NTO (UF-NTO) and its formulation with Al nanopowder has been developed. Results from small-scale sensitivity tests on both the UF-NTO and aluminized NTO composite indicated that they are insensitive to impact, friction and HESD. The performance of both UF-NTO and NTO/Al mix was evaluated by,detonation-spreading floret tests. At the same pressed density, it was found that, when initiated by a 3-mm-diameter flyer plate, the aluminized NTO composite produced a shallower dent on a copper witness plate than neat UF-NTO and thus was inferior to UF-NTO in detonation spreading. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lee, KY (reprint author), Los Alamos Natl Lab, MS C920,POB 1663, Los Alamos, NM 87545 USA. EM leeka@uclink.berkeley.edu NR 7 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 855 EP 858 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000199 ER PT S AU Mulford, R Swift, D AF Mulford, R Swift, D BE Furnish, MD Gupta, YM Forbes, JW TI Reactive flow in nitromethane using a quasiharmonic unreacted equation of state SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID SHOCK INITIATION; SPECTROSCOPY; DETONATION AB This work examines the suitability of an Arrhenius reaction rate for describing homogeneous initiation of nitromethane, CH3NO2. We use reactive flow models that include temperature as well as mechanical state to investigate shock initiation in nitromethane. We describe the construction of an unreacted equation of state to provide the accurate temperatures required to support a PF temperature dependent reaction rate within a reactive flow model. A quasiharmonic form based on the Gruneisen equations of state normalized to shock wave data but with a more rigorous treatment of thermal modes was used. A thermochemical model was used for the reaction products. The Arrhenius reaction parameters reported in the literature reproduced experimental data within this model, without adjustment. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mulford, R (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 17 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 875 EP 878 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000204 ER PT S AU Strachan, A van Duin, ACT Goddard, WA AF Strachan, A van Duin, ACT Goddard, WA BE Furnish, MD Gupta, YM Forbes, JW TI Initial chemical events in the energetic material RDX under shock loading: Role of defects SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We use the recently developed reactive force field ReaxFF with molecular dynamics (MD) to study the role of voids on the initial chemical events in the high-energy material RDX under shock loading. We find that for strong shocks (particles velocity of 3 km/s) very small gaps (2 nm) lead to important overheating (similar to 1000 K). This over-heating facilitates chemical reactions and leads to a larger production of small molecules (such as NO2, NO, OH) than in perfect crystals shocked with the same strength. The chemical reactions occur after the void has collapsed and the ejected material re-compressed rather than when hot molecules are ejected out of the downstream surface. C1 Los Alamos Natl Lab, Theoet Div, Los Alamos, NM 87545 USA. RP Strachan, A (reprint author), Los Alamos Natl Lab, Theoet Div, POB 1663, Los Alamos, NM 87545 USA. EM strachan@lanl.gov NR 8 TC 2 Z9 2 U1 3 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 895 EP 898 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000209 ER PT S AU Tarver, CM AF Tarver, CM BE Furnish, MD Gupta, YM Forbes, JW TI On the existence of pathological detonation waves SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Pathological detonation waves with velocities greater than Chapman-Jouguet (C-J) have been proposed theoretically but never observed experimentally in gaseous, liquid or solid explosives. Two types of pathological chemical reaction zones have been identified within the Zeldovich - von Neumann - Doring (ZND) model: an exothermic chemical decomposition with a mole decrease from the von Neumann spike state to the C-J state; and an exothermic reaction followed by an endothermic reaction (eigenvalue detonation). The high temperatures reached in detonation reaction zones cause sufficient radial and atom formation to insure that enough moles are formed in gaseous 2H(2) + O-2 detonations. Aluminized explosives exhibit a slight mole decrease when the solid aluminum particles are oxidized, but this does not negate the large mole increase that occurs during explosive decomposition. Porous solid explosives whose products form with more cold compression energy than that of the solid are still a possibility for pathological detonation. Eigenvalue detonations have been postulated for H-2 + Cl-2 gas phase detonations and for plastic bonded solid explosives if endothermic binder decomposition follows exothermic explosive decomposition. Chemical kinetic and physical arguments are presented to eliminate these possible pathological detonations. In the case of H-2 + Cl-2, highly vibrationally excited HCl molecules dissociate Cl-2 molecules during the exothermic portion of the reaction zone rather than later in the flow process. In the plastic bonded explosives, the binders are located on the surfaces of explosive particles and thus are exposed to hot spots created by the three-dimensional Mach stem shock front. Any remaining binder material rapidly reacts in collisions with the high, vibrationally excited reaction products formed during explosive decomposition. Therefore eigenvalue detonations are extremely unlikely to occur in gaseous, liquid or solid explosives. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Tarver, CM (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. EM tarver1@llnl.gov NR 11 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 902 EP 905 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000211 ER PT S AU Browning, RV Peterson, PD Roemer, EL Scammon, RJ AF Browning, RV Peterson, PD Roemer, EL Scammon, RJ BE Furnish, MD Gupta, YM Forbes, JW TI Grit particle enhanced non-shock ignition of explosives SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Grit particles are used in explosive sensitivity tests, such as the drop weight impact test and the drop skid test, as sensitizing agents. In this paper we examine characteristics of common natural and industrial grit particles. They are observed in a wide variety of sizes and shapes. The fine particles can easily migrate around a facility and potentially become embedded in explosive surfaces. To study the effects of grit particles on ignition behavior we identify a simple configuration of particles cutting or grooving adjacent metal surfaces. We then present a process for analyzing the ignition characteristics. Estimates of the effective flow and fracture strength of the metals and explosive composites. on a scale of 1 to 100 microns, are used in chip forming models to calculate chip temperatures. Ignition characteristics are studied using a reactive heat transfer model of individual chips. as cut by grit particles, and held against an explosive surface. The models indicate that very small particles can cause ignition of adjacent explosives given the temperatures resulting from the chip forming process. These simulations are summarized in terms of non-dimensional variables. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Browning, RV (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM rvb@lanl.gov; pdp@lanl.gov NR 8 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 921 EP 924 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000215 ER PT S AU Garcia, F Vandersall, KS Forbes, JW Tarver, CM Greenwood, D AF Garcia, F Vandersall, KS Forbes, JW Tarver, CM Greenwood, D BE Furnish, MD Gupta, YM Forbes, JW TI Pressure wave measurements resulting from thermal cook-off of the HMX based high explosive LX-04 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Experiments that investigate thermal and nearby explosion scenarios are needed to provide essential data to models for accurate predictions. A porous LX-04 (85/15 wt% HMX/Viton) sample was heated in a heavily confined donor charge until it thermally exploded. The reaction accelerated a steel cover plate across a 10 cm gap into a preheated gauged acceptor cylinder (near its theoretical maximum density) of LX-04. The carbon resistor gauges in the acceptor measured the resulting multi-dimensional ramp wave as it propagated through the pre-heated LX-04. Detonation of the LX-04 acceptol does not occur. Results are compared to similar experiments with acceptors at room temperature. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Garcia, F (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM garcia13@llnl.gov; vandersalll@lln1.gov; jfor@direcway.com; tarver1@ltnl.gov; jfor@direcway.com NR 8 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 947 EP 950 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000221 ER PT S AU Gustavsen, RL Sheffield, SA Alcon, RR AF Gustavsen, RL Sheffield, SA Alcon, RR BE Furnish, MD Gupta, YM Forbes, JW TI Shock initiation of "virgin" and "recycled" PBX 9502 measured with embedded electromagnetic particle velocity gauges SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We have completed a series of shock initiation experiments on two types of PBX 9502 (95 weight % dry aminated TATB explosive 5 weight % Kel-F 800 binder). "Virgin" PBX 9502 contains 100% newly formulated material. "Recycled" PBX 9502 contains 50% new material and 50% ground up PBX 9502 machining scraps. It was formulated because of the expense of manufacturing TATB. Experiments were performed on a two stage gas gun at Los Alamos. Samples were prepared with ten or eleven embedded electromagnetic particle velocity gauges to measure the evolution of the wave leading up to a detonation. Additionally, one to three shock tracker gauges were used to track the position of the shock front with time and deter-mine the point where detonation was achieved. Analysis yielded particle velocity - shock velocity (U-s - u(p)) Hugoniot points and run distances and times to detonation as a function of initial pressure. All results are consistent with previously published results on a different lot of Virgin PBX 9502 which were obtained with different experimental techniques. No significant differences in the shock sensitivity of the two formulations were observed. C1 Los Alamos Natl Lab, Grp DX 2, Los Alamos, NM 87545 USA. RP Gustavsen, RL (reprint author), Los Alamos Natl Lab, Grp DX 2, POB 1663, Los Alamos, NM 87545 USA. EM rgus@lanl.gov NR 5 TC 5 Z9 5 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 973 EP 976 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000227 ER PT S AU Harry, HH Uher, KJ Hagelberg, SI AF Harry, HH Uher, KJ Hagelberg, SI BE Furnish, MD Gupta, YM Forbes, JW TI The Poly-rho test as a tool for screening explosive performance SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB A screening test was developed that can be used to decide if a new synthesized/formulated explosive might warrant further development. The test consists of a rate stick composed of 12.7 mm diameter by 12.7 mm. high pellets of different densities ordered from lowest to highest, with ignition occurring at the low-density end of the stick. This "Poly-rho" test yields detonation velocities over a range of densities using only the small amount of the explosive typically generated by the synthetic organic chemist at an early stage of the scale-up process. The amount of material required is far less than that required for the typical rate stick series. Poly-rho tests on two explosives commonly used at Los Alamos National Laboratory, PBX 9501 and PBX 9502, were conducted and the results compared with empirical detonation-theory predictions and others' explosive experiments. There was good agreement in both cases. C1 Los Alamos Natl Lab, Mat Dynam Grp, Los Alamos, NM 87545 USA. RP Harry, HH (reprint author), Los Alamos Natl Lab, Mat Dynam Grp, POB 1663, Los Alamos, NM 87545 USA. EM harry_bert@lanl.gov NR 5 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 977 EP 980 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000228 ER PT S AU Henson, BF Smilowitz, L Asay, BW Romero, JJ Oschwald, DM Dickson, PM AF Henson, BF Smilowitz, L Asay, BW Romero, JJ Oschwald, DM Dickson, PM BE Furnish, MD Gupta, YM Forbes, JW TI Measurement of the specific area of HMX and PBX 9501 by physical adsorption SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We present physical adsorption data on HMX and PBX 9501. Adsoiption isotherms were obtained by pressure measurements using Krypton at liquid nitrogen temperatures. The data were analyzed to obtain the specific area of the samples. We observed a particle size dependence in the HMX crystals with small crystals having specific areas consistent with a solid geometric particle with the aspect ratio of an oblate spheroid. The larger particles, however, had specific areas above those predicted by the simple geometric surface area. This implies that the surface area of the larger particles is dominated by internal porosity and is relatively independent of particle size above approximately 100 micron diameter. The specific area of PBX 9501 was measured and agreed with that predicted by a calculation based on the particle size distribution and measured specific area of the component crystals. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Henson, BF (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM smilo@lanl.gov; bwa@lanl.gov; oschwald@lanl.gov; dickson@lanl.gov NR 1 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 981 EP 984 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000229 ER PT S AU Hooks, DE Dick, JJ Martinez, AR AF Hooks, DE Dick, JJ Martinez, AR BE Furnish, MD Gupta, YM Forbes, JW TI Shock experiments on explosive single, crystals SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID PENTAERYTHRITOL TETRANITRATE; DETONATION; HMX AB An increasing interest in the properties of single crystals of high explosives necessitates a continuing supply of these crystal samples. An overview of our capabilities for single crystal sample preparation and characterization will be discussed. Large single crystals are grown, then cut along specific Miller planes and polished. Perfection and orientation are confirmed through optical techniques and transmission Laue X-ray diffraction. Gas-gun impact experiments were performed on three orientations of HMX crystals. The experiments measured decay of the elastic precursor shock along the (110), (011), and (010) planes. The results show that the (010) plane has higher strength and lower decay rates, by a factor of almost 2, than the other two. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hooks, DE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM dhooks@lanl.gov; armartinez@lanl.gov NR 12 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 985 EP 988 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000230 ER PT S AU Horie, Y Hamate, Y Greening, D Dey, T AF Horie, Y Hamate, Y Greening, D Dey, T BE Furnish, MD Gupta, YM Forbes, JW TI Reactive burn modeling of solid explosives with a statistical treatment of hot spots in two spatial dimensions SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB This paper is a companion report to "A Statistical Approach on Mechanistic Modeling of High Explosives Ignition" in this proceedings. We present a generalization of the bum model for applications in multi-dimensions. The model is implemented on the hydrocode called "CASH." We describe two test calculations in a cylindrical geometry. The first is concerned with the ignition by impact, followed by quenching. The second is the propagation of a steady detonation wave. C1 Los Alamos Natl Lab, Appl Phys Div, Los Alamos, NM 87545 USA. RP Horie, Y (reprint author), Los Alamos Natl Lab, Appl Phys Div, Los Alamos, NM 87545 USA. EM horie@lanl.gov; hamate@lanl.gov NR 16 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 989 EP 992 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000231 ER PT S AU Parker, GR Asay, BW Dickson, PM Henson, BF Smilowitz, LB AF Parker, GR Asay, BW Dickson, PM Henson, BF Smilowitz, LB BE Furnish, MD Gupta, YM Forbes, JW TI Effect of thermal damage on the permeability of PBX 9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB It has been known for many years that thermally-damaged explosive has significantly different mechanical properties when compared to its pristine state. These differences can have profound effects on the response to external stimuli. We present the results of a study to examine the effects of dynamic thermal damage on the permeability of PBX 9501 and compare these results with a nonenergetic simulant. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Parker, GR (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM gparker@lanl.gov; bwa@lanl.gov; dickson@lanl.gov; henson@lanl.gov; smilo@lanl.gov NR 4 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1009 EP 1012 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000236 ER PT S AU Saw, CK Tarver, CM AF Saw, CK Tarver, CM BE Furnish, MD Gupta, YM Forbes, JW TI Binder/HMX interaction in PBX9501 at elevated temperatures SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID DELTA PHASE-TRANSITION AB Plastic bonded explosives (PBX) generally consist of 85-95% by weight energetic material, such as HMX, and 5-15% polymeric binder. Understanding of the structure and morphology at elevated temperatures and pressures is important for predicting of PBX behavior in accident scenarios. The crystallographic behavior of pure HMX has been measured as functions of temperature and grain size. The investigation is extended to the high temperature behavior of PBX 9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/F). The results show that the HMX beta- to delta-phase transition in PBX 9501 is similar to that in neat MAX. However, in the presence of the PBX 9501 binder, delta-phase HMX readily converts back to beta-phase during cooling. Using the same temperature profile, the conversion rate decreases for each subsequent heating and cooling cycle. As observed in earlier experiments, no reverse conversion is observed without the polymer binder. It is proposed that the reversion of delta-phase to beta-phase is due to changes in the surface molecular potential caused by the influence of the polymer binder on the delta-phase. Upon thermal cycling, the polymer binder segregates from the HMX particles and thus reduces the influence of the binder on the surface molecules. This segregation increases the resistance for the delta-phase to beta-phase transition, as demonstrated in an aged PBX 9501 material for which the reversion is not observed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Saw, CK (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave L-350, Livermore, CA 94551 USA. EM sawl@llnl.gov; tarverl@llnl.gov NR 8 TC 5 Z9 5 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1029 EP 1032 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000241 ER PT S AU Sheffield, SA Gustavsen, RL Alcon, RR Robbins, DL Stahl, AB AF Sheffield, SA Gustavsen, RL Alcon, RR Robbins, DL Stahl, AB BE Furnish, MD Gupta, YM Forbes, JW TI High pressure Hugoniot and reaction rate measurements in PBX9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Single-stage and two-stage gas gun experiments have been completed to measure the unreacted Hugoniot of PBX9501 high explosive (HE). Two types of experiments were done: 1) PBX9501 was impacted with a higher impedance projectile and the interface particle velocity history was measured using a magnetic gauge glued to the HE front; 2) a PBX9501 disc was mounted in the front of a projectile that impacted a LiF window and velocity interferometers (VISAR) were used to measure the impact interface particle velocity history. Inputs to the PBX9501 ranged from 3 to 15 GPa in these experiments. Particle velocity waveforms show an induction time followed by a particle velocity change (the nature of the change depends on the type of experiment) corresponding to shock-induced reaction in the PBX9501. The induction part of the waveform provided unreacted Hugoniot information so several new high-pressure Hugoniot points were generated. These data do not indicate a softening in the unreacted Hugoniot at high pressures; more experiments will be necessary to determine this. By using an estimate for the reaction product EOS, it was possible to estimate the average PBX9501 initial reaction rate for each experiment. The induction time decreases with pressure and the reaction rate increases with pressure. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sheffield, SA (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM ssheffield@lanl.gov; rgus@lanl.gov; robbins@lanl.gov NR 7 TC 2 Z9 2 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1033 EP 1036 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000242 ER PT S AU Smilowitz, L Henson, BF Asay, BW Dickson, PM Oschwald, DM Romero, JJ Parker, G AF Smilowitz, L Henson, BF Asay, BW Dickson, PM Oschwald, DM Romero, JJ Parker, G BE Furnish, MD Gupta, YM Forbes, JW TI Morphology changes during thermal decomposition of PBX9501 SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID DELTA PHASE-TRANSITION; OCTAHYDRO-1,3,5,7-TETRANITRO-1,3,5,7-TETRAZOCINE; EXPLOSIVES AB Our goal is to be able to predict the morphology of PBX9501 as a function of time at temperature. This is necessary in order to be able to predict the behavior of material that has been subjected to a known temperature trajectory. We have begun by studying the mechanism of the initial solid state phase transition between the beta and delta phases of HMX. This leads to a volume expansion and a large degree of mechanical damage in the material. On continued heating above the solid-solid phase transition, a solid to gas transformation occurs. We have monitored the solid to gas transition as a function of isothermal temperature and particle size in order to address mechanistic questions concerning chemical production of gas phase species by surface regression or internal pore formation. We have also performed experiments to characterize the morphology changes in the material caused by the loss of solid mass. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Smilowitz, L (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM smilo@lanl.gov; henson@lanl.gov; bwa@lanl.go; dickson@lanl.gov; oschwald@lanl.gov NR 16 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1037 EP 1040 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000243 ER PT S AU Straight, JW Idar, DJ Smith, L Osborn, MA Viramontes, LE Chavez, PJ AF Straight, JW Idar, DJ Smith, L Osborn, MA Viramontes, LE Chavez, PJ BE Furnish, MD Gupta, YM Forbes, JW TI Measuring the energy release of low amplitude impact of high explosive events SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Predicting the degree of violence of high explosive (HE) reactions for a given event is desirable for risk assessments and a goal for computational models. Historically, different types of low amplitude impact tests on HE specimens have been performed to determine the critical impact-velocity threshold for high explosive violent reactions (HEVR). Additionally, the energy release relative to a steady-state detonation is also desirable for assessing the potential outcome of an accidental event. Traditionally, blast gauge measurements have been used to measure the overpressure of the HEVR event at a defined distance. This paper summarizes the use of this active technique coupled with a passive technique to derive average energy release curves for Modified Steven tests. A classic ballistic pendulum design was employed with the traditional blast gauge method. Calibration of the ballistic pendulum involved three elements. First, two mechanical measurements were related to the actual peak swing of the pendulum. Second, the general nature of the swing versus energy release curve was estimated. Two different approaches were used to estimate the momenta as a function of HE energy release using the Gurney relationships for an unsymmetrical sandwich. Finally, both techniques were simultaneously benchmarked with PBX 9501 calibration charges. Test results demonstrate the utility of using coupled diagnostic methods for low amplitude insult testing. Each set of data was fit to derive a working curve for the determination of the average energy release for HEVR event based on mass relative to a steady-state detonation. These tests results and working curve derivations are presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Straight, JW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM straight@lanl.gov; djidar@lanl.gov NR 3 TC 0 Z9 0 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1041 EP 1044 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000244 ER PT S AU Switzer, LL Vandersall, KS Chidester, SK Greenwood, DW Tarver, CM AF Switzer, LL Vandersall, KS Chidester, SK Greenwood, DW Tarver, CM BE Furnish, MD Gupta, YM Forbes, JW TI Threshold studies of heated HMX-based energetic material targets using the Steven Impact Test SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID EXPLOSIVES; IGNITION AB Impact tests performed at low velocity on heated energetic material samples are of interest when considering the situation of energetic materials involved in a fire. To determine heated reaction thresholds, Steven Test targets containing PBX 9404 or LX-04 samples heated to the range of 150-170degreesC were impacted at velocities up to 150 m/s by two different projectile head geometries. Comparing these measured thresholds to ambient temperature thresholds revealed that the heated LX-04 thresholds were considerably higher than ambient, whereas the heated PBX 9404 thresholds were only slightly higher than the ambient temperature thresholds. The violence of reaction level of the PBX 9404 was considerably higher than that of the LX-04 as measured with four overpressure gauges. The varying results in these samples with different HMX/binder configurations indicate that friction plays a dominant role in reaction ignition during impact. This work outlines the experimental details, compares the thresholds and violence levels of the heated and ambient temperature experiments, and discusses the dominant mechanisms of the measured thresholds. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Switzer, LL (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM vandersall1@llnl.gov; chidesterl@llnl.gov; tarverl@llnl.gov NR 10 TC 3 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1045 EP 1048 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000245 ER PT S AU Urtiew, PA Forbes, JW Tarver, CM Vandersall, KS Garcia, F Greenwood, DW Hsu, PC Maienschein, JL AF Urtiew, PA Forbes, JW Tarver, CM Vandersall, KS Garcia, F Greenwood, DW Hsu, PC Maienschein, JL BE Furnish, MD Gupta, YM Forbes, JW TI Shock sensitivity of LX-04 containing delta phase HMX at elevated temperatures SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB LX-04 is a widely used HMX-based plastic bonded explosive, which contains 85 weight % HMX and 15 weight % Viton binder. The sensitivity of LX-04 to a single stimulus such as heat, impact, and shock has been previously studied. However, hazard scenarios can involve multiple stimuli, such as heating to temperatures close to thermal explosion conditions followed by fragment impact, producing a shock in the hot explosive. The sensitivity of HMX at elevated temperatures is further complicated by the beta to delta solid-state phase transition, which occurs at approximately 165degreesC. This paper presents the results of shock initiation experiments conducted with LX-04 preheated to 190degreesC, as well as density measurements and small scale safety test results of the delta phase HMX at room temperature. This work shows that LX-04 at 190degreesC is more shock sensitive than LX-04 at 150degreesC or 170degreesC due to the volume increase during the beta to delta solid phase transition, which creates more hot spots, and the faster growth of reaction during shock compression. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Urtiew, PA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM urtiewl@llnl.gov; jfor@direcway.com; vandersalll@llnl.gov; garcia13@llnl.gov; jfor@direcway.com NR 11 TC 10 Z9 11 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1053 EP 1056 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000247 ER PT S AU Vandersall, KS Murty, SS Chidester, SK Forbes, JW Garcia, F Greenwood, DW Tarver, CM AF Vandersall, KS Murty, SS Chidester, SK Forbes, JW Garcia, F Greenwood, DW Tarver, CM BE Furnish, MD Gupta, YM Forbes, JW TI Investigation of Steven Impact Test using a transportation hook projectile with gauged experiments and 3D modeling SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID EXPLOSIVES; IGNITION AB The Steven Impact Test and associated modeling offer valuable practical predictions for evaluating numerous safety scenarios involving low velocity impact of energetic materials by different projectile geometries. One such scenario is the impact of energetic material by a transportation hook during shipping, which offers complexity because of the irregular hook projectile shape. Experiments were performed using gauged Steven Test targets with PBX9404 impacted by a transportation hook projectile to compliment previous non-gauged experiments that established an impact threshold of approximately 69 m/s. Modeling of these experiments was performed with LS-DYNA code using an Ignition and Growth reaction criteria with a friction term. Comparison of the experiment to the model shows reasonable agreement with some details requiring more attention. The experimental results (including carbon resistor gauge records), model calculations, and a discussion of the dominant reaction mechanisms in light of comparisons between experiment and model will be presented. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Vandersall, KS (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM chidesterl@ltnl.gov; jfor@direcway.com; garcia13@llnl.gov; tarverl@llnl.gov; jfor@direcway.com NR 13 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1057 EP 1060 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000248 ER PT S AU Vitello, P Fried, LE Pudliner, B McAbee, T AF Vitello, P Fried, LE Pudliner, B McAbee, T BE Furnish, MD Gupta, YM Forbes, JW TI Sparse partial equilibrium tables in chemically resolved reactive flow SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID DETONATION; INITIATION AB The detonation of an energetic material is the result of a complex interaction between kinetic chemical reactions and hydrodynamics. Unfortunately, little is known concerning the detailed chemical kinetics of detonations in energetic materials. CHEETAH uses rate laws to treat species with the slowest chemical reactions, while assuming other chemical species are in equilibrium. CHEETAH supports a wide range of elements and condensed detonation products and can also be applied to gas detonations. A sparse hash table of equation of state values is used in CHEETAH to enhance the efficiency of kinetic reaction calculations. For large-scale parallel hydrodynamic calculations, CHEETAH uses parallel communication to updates to the cache. We present here details of the sparse caching model used in the CHEETAH coupled to an ALE hydrocode. To demonstrate the efficiency of modeling using a sparse cache model we consider detonations in energetic materials. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Vitello, P (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM vitello@llnl.gov; fried1@llnl.gov RI Fried, Laurence/L-8714-2014 OI Fried, Laurence/0000-0002-9437-7700 NR 10 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1061 EP 1064 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000249 ER PT S AU Zhang, DZ AF Zhang, DZ BE Furnish, MD Gupta, YM Forbes, JW TI Shock dispersion in composite material with polymer binder SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Many composite materials consist of elastic particles held together by a soft polymeric binder. Usually, the stress in the binder is strain rate dependent. Although in many cases the binder only occupies a few percent of the volume of the material, the macroscopic strain and strain rate of the composite come mainly from the deformation of the binder. For this reason, the strain and strain rate experienced by the binder are usually an order of magnitude larger than the macroscopic strain and strain rate of the composite, and the composite is more sensitive to the strain rate than the binder itself. To model shock wave propagation in the composite, it is essential to correctly account for the stress relaxation in the polymer. Modeling polymer behavior undergoing high strain rate deformations has been a challenge for many conventional polymer models. Recently, based on non-equilibrium deformation of polymer segments, a new constitutive relation for polymer gels has been developed. A distinguishing feature of the new polymer model is that for a short time, the stress relaxation kernel is inversely proportional to the square root of time. The kernel asymptotes to an exponentially decaying function only for long relaxation times. Based on the newly developed polymer model, a simple model for the particle-binder composite is obtained. Numerical simulations are carried out to compare shock wave profiles obtained from plate impact experiments at various shock strengths. Excellent agreements are found. C1 Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, Los Alamos, NM 87545 USA. RP Zhang, DZ (reprint author), Los Alamos Natl Lab, Div Theoret, Fluid Dynam Grp, T-3,B216, Los Alamos, NM 87545 USA. EM dzhang@lanl.gov NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1073 EP 1076 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000252 ER PT S AU Funk, DJ Meserole, CA Hof, DE Fisher, GL Roberts, J Taylor, AJ Lee, HJ Workman, J McCulloch, Q AF Funk, DJ Meserole, CA Hof, DE Fisher, GL Roberts, J Taylor, AJ Lee, HJ Workman, J McCulloch, Q BE Furnish, MD Gupta, YM Forbes, JW TI An ultrafast X-ray diffraction apparatus for the study of shock waves SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID PHASE-TRANSITIONS; GENERATION; SILICON; PULSES AB The use of X-ray diffraction for the study of shock physics has been pursued for decades. Conceptually, changes in the diffraction line, including broadening and shifts, provide details about the nature of compression, plasticity, phase, and kinetics of the phase transition for the material being shock-loaded. In practice, X-ray source brightness, sample preparation, and turn-around times have limited the applicability to a few crystalline systems. We report our development of an ultrafast X-ray diffraction instrument suitable for studying rapid phase changes, including both solid-solid and solid-melt, in shock-loaded materials. Due to the relatively small sample sizes needed and to the ability to conduct thousands of shock physics experiments with these small samples, we can build up the statistics required to study elastic-plastic transitions, the kinetics of phase changes, as well as the mechanistic details of phase changes in nearly all materials, including high-Z samples. An overview of the technique and our initial source characterization are discussed. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Funk, DJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM djf@lanl.gov; meserole@lanl.gov NR 15 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1155 EP 1158 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000271 ER PT S AU Furnish, MD Trott, WM Mason, J Podsednik, J Reinhart, WD Hall, C AF Furnish, MD Trott, WM Mason, J Podsednik, J Reinhart, WD Hall, C BE Furnish, MD Gupta, YM Forbes, JW TI Assessing mesoscale material response via high-resolution line-imaging visar SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Of special promise for providing dynamic mesoscale response data is the line-imaging VISAR, an instrument for providing spatially resolved velocity histories in dynamic experiments. We have prepared a line-imaging VISAR system capable of spatial resolution in the 10 - 20 micron range. We are applying this instrument to selected experiments on a compressed gas gun, chosen to provide initial data for several problems of interest, including: (1) pore-collapse in single-crystal copper (70 micron diameter hole; 2 different versions); and (2) response of a welded joint in dissimilar materials (Ta, Nb) to ramp loading relative to that of a compression joint. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Furnish, MD (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM mdfurni@sandia.gov; wdreinh@sandia.gov; chall@sandia.gov; mdfurni@sandia.gov NR 4 TC 4 Z9 4 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1159 EP 1162 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000272 ER PT S AU Lemke, RW Knudson, MD Davis, JP Bliss, DE Harjes, HC AF Lemke, RW Knudson, MD Davis, JP Bliss, DE Harjes, HC BE Furnish, MD Gupta, YM Forbes, JW TI Self consistent, 2D magneto-hydrodynamic simulations of magnetically driven flyer plate experiments on the Z-machine SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID ISENTROPIC COMPRESSION AB The intense magnetic field generated in the 20 MA Z-machine is used to accelerate metallic flyer plates to high velocity (peak velocity similar to 20-30 km/s) for the purpose of generating strong shocks (peak pressure similar to 5-10 Mb) in equation of state experiments. We have used the Sandia developed, 2D magneto-hydrodynamic (MHD) simulation code ALEGRA to investigate the physics of accelerating flyer plates using multi-megabar magnetic drive pressures. Through detailed analysis of experimental data using ALEGRA, we developed a 2D, predictive MHD model for simulating material science experiments on Z. The ALEGRA MHD model accurately produces measured time dependent flyer velocities. Details of the ALEGRA model are presented. Simulation and experimental results are compared and contrasted for shots using standard and shaped cur-rent pulses whose peak drive pressure is similar to2 Mb. Isentropic compression of Al to 1.7 Mb is achieved by shaping the current pulse. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lemke, RW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM rwlemke@sandia.gov; mdknuds@sandia.gov; jpdavis@sandia.gov NR 14 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1175 EP 1180 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000276 ER PT S AU McGrane, SD Moore, DS Funk, DJ AF McGrane, SD Moore, DS Funk, DJ BE Furnish, MD Gupta, YM Forbes, JW TI Measurement of shocked thin polymer film Hugoniot properties with ultrafast dynamic ellipsometry SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID VIBRATIONAL SPECTROSCOPY; WAVE AB The shocked refractive index, particle velocity, and shock velocity are determined for laser shocked transparent thin polymer films using multiple angle/multiple polarization ultrafast microscopic interferometry to measure dynamic ellipsometric properties. The interferometry of shocked thin films exhibits phase shifts caused by (1) surface displacement of the Al/thin film interface and (2) interference of multiple reflections off the moving shocked/unshocked thin film interface. Results from interferometric measurements as a function of shock strength over the range 2-20 GPa illustrate that 625 nm polymethylmethacrylate films have the same material response to shock loa ding (Hugoniot) as macroscopic samples [1] shocked with traditional plane wave generation techniques (from literature). Results for polyvinylnitrate thin films are presented over the range approximately 2-22 GPa. C1 Los Alamos Natl Lab, Mat Dynam Grp, Los Alamos, NM 87544 USA. RP McGrane, SD (reprint author), Los Alamos Natl Lab, Mat Dynam Grp, MS P952, Los Alamos, NM 87544 USA. EM mcgrane@lanl.gov; moored@lanl.gov; djf@lanl.gov RI Moore, David/C-8692-2013 NR 17 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1181 EP 1186 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000277 ER PT S AU Meserole, CA Fisher, GL Funk, DJ AF Meserole, CA Fisher, GL Funk, DJ BE Furnish, MD Gupta, YM Forbes, JW TI Synthesis of ideal iron film samples for shock physics experiments using ultrafast X-ray diffraction SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID GROWTH; MGO; FE AB The fabrication of iron (Fe) films epitaxially grown on single crystal magnesium oxide (MgO) substrates is presented. Our goal is the creation of ideal crystalline iron samples for shock physics experiments using ultrafast x-ray diffraction. There are several reasons for the choice of the Fe/MgO system. Iron is known to undergo shock-induced structural changes, and MgO is selected because it is a) transparent to the laser light used to generate the shock in the Fe film and b) there is only a 4% lattice mismatch between Fe and MgO. Issues such as generating a specific crystallographic orientation in the iron film and technical challenges in the synthetic process are discussed. The ultimate goal for producing a single crystal Fe film on MgO is to allow the merger of theory and experiment. A new ultrafast x-ray diffraction experiment will permit the detection of laser-driven shock-induced phase changes in the crystalline Fe samples. These experiments will complement an elegant MD investigation of a shocked Fe crystal.p C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Meserole, CA (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM meserole@lanl.gov; rocj/foscjer@nrl.navy.mil; djf@lanl.gov NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1187 EP 1190 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000278 ER PT S AU Reinovsky, RE Anderson, WE Atchison, WL Faehl, RJ Keinigs, RK Lindemuth, IR Thompson, MC Taylor, A AF Reinovsky, RE Anderson, WE Atchison, WL Faehl, RJ Keinigs, RK Lindemuth, IR Thompson, MC Taylor, A BE Furnish, MD Gupta, YM Forbes, JW TI Shock-wave and material properties experiments using the Los Alamos atlas pulsed power system SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The Atlas facility built by Los Alamos is the world's first and only laboratory pulsed power system designed specifically to provide capability for shock-wave physics, materials properties, instability, and hydrodynamics experiments in converging geometry. Constructed in 2000 and commissioned in August 2001, Atlas completed its first year of physics experiments in October 2002, using ultra high precision magnetically imploded, cylindrical liners to reliably and reproducibly convert electrical energy to hydrodynamic energy in targets whose volume is many cubic centimeters. Multi-view (transverse and axial) radiography, laser-illuminated shadowgraphy, and VISAR measurements of liner and target surface motion, in addition to electrical diagnostics, provide a detailed description of the behavior of the experimental package. In the first year material damage and failure experiments, dynamic friction experiments, and a family of converging shock experiments were conducted in addition to a detailed series of liner implosion characterization experiments. These experiments will continue and additional series to evaluate material strength at very high rates of strain, ejecta. formation from surfaces, and instability growth at interfaces will be added in the future. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Reinovsky, RE (reprint author), Los Alamos Natl Lab, MS D420, Los Alamos, NM 87545 USA. EM bobr@lanl.gov; dkgraff@lanl.gov; e.a.taylor@open.ac.uk NR 5 TC 4 Z9 5 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1191 EP 1194 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000279 ER PT S AU Lawrence, RJ Grady, DE Hall, CA AF Lawrence, RJ Grady, DE Hall, CA BE Furnish, MD Gupta, YM Forbes, JW TI The response of ceramic powders to high-level quasi-isentropic dynamic loads SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The pulse-power machine, in an isentropic compression experiment (ICE) mode, will allow the dynamic characterization of porous materials-here various ceramic powders, e.g., Al2O3, WC, ZrO2-at roughly half their solid densities. A cylindrical configuration can provide megabar-level loads on an annulus of the sample material. Data will be provided by velocity interferometers that measure free-surface (or possibly interface) particle velocities. Differing sample thicknesses using stepped or conical geometries yield experimental efficiency by allowing multiple data records on single shots. With the p/alpha model for porous materials, the one-dimensional Lagrangian hydrocode WONDY provides the needed analyses. Based on static data, both power-law and quadratic crush curves are employed. Within the model constraints, we suggest that the most important parameter for characterizing the material is the crush strength, p(s). With adequate sample thicknesses, the planned velocity measurements differentiate among the various assumptions for p(s). C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lawrence, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM rjlawre@sandia.gov; dgrady@ara.com; chall@sandia.gov NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1213 EP 1216 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000284 ER PT S AU Nguyen, JH Orlikowski, D Streitz, FH Holmes, NC Moriarty, JA AF Nguyen, JH Orlikowski, D Streitz, FH Holmes, NC Moriarty, JA BE Furnish, MD Gupta, YM Forbes, JW TI Specifically prescribed dynamic thermodynamic paths and resolidification experiments SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID ISENTROPIC COMPRESSION EXPERIMENTS; CONSTITUTIVE MODEL; PHASE-TRANSITIONS; Z-ACCELERATOR; BISMUTH; SOLIDS; LIQUID AB We describe here a series of dynamic compression experiments using impactors with specifically prescribed density profiles. These functionally graded density impactors are composed of materials whose densities vary from about 0.1 g/cc to more than 15 g/cc. The density profile of these impactors can be tailored to generate specifically prescribed thermodynamic paths in the samples. These paths include quasi-isentropes as well as combinations of shocks, releases and quasi-isentropic compressions. The time-scale of these experiments ranges from nanoseconds to several microseconds. The strain-rates in the quasi-isentropic compression experiments vary from approximately 10(S)(4)(-1) to 10(S)(6)(-1). We applied the quasi-isentropic compression technique to study resolidification of molten bismuth and water. In the water experiments, the observed particle velocity exhibits a two-wave structure and the water-ice phase transition time scales consistently with the sample thickness. Hydrodynamic simulations also suggest resolidification of bismuth. However, the calculated sound velocities of bismuth need further investigation. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nguyen, JH (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 25 TC 17 Z9 19 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1225 EP 1230 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000287 ER PT S AU Tasker, DG Goforth, JH Oona, H Fowler, CM King, JC Herrera, D Torres, D AF Tasker, DG Goforth, JH Oona, H Fowler, CM King, JC Herrera, D Torres, D BE Furnish, MD Gupta, YM Forbes, JW TI Advances in isentropic compression experiments (ICE) using high explosive pulsed power SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We are developing a prototype high explosive pulsed power (HEPP) system to obtain isentropic Equation of State (EOS) data with the Asay technique [1]. Our prototype system comprises a flat-plate explosive driven magnetic flux compression generator (FCG), an explosively formed fuse (EFF) opening switch, and a series of explosively-actuated closing switches. The FCG is capable of producing similar to10 MA into suitable loads, and, at a length of 216 mm, the EFF will sustain voltages in excess of 200 M The load has an inductance of similar to3 to 10 nH, allowing up to similar to7 MA to be delivered in times of similar to0.5 mus. This prototype will produce isentropic compression profiles in excess of 2 Mbar in a material such as tungsten. We will obtain isentropic EOS data for copper at pressures up to similar to1.5 Mbar with the prototype system, immediately after this conference; eventually we plan to reach several tens of Mbar with larger, more advanced systems. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tasker, DG (reprint author), Los Alamos Natl Lab, DX-2, Los Alamos, NM 87545 USA. EM tasker@lanl.gov NR 8 TC 2 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1239 EP 1242 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000290 ER PT S AU Baer, BJ Yoo, CS AF Baer, BJ Yoo, CS BE Furnish, MD Gupta, YM Forbes, JW TI Vibrational spectra of dense molecular fluids in a laser-heated dac: Implications to shock compressed fluids SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID STOKES-RAMAN-SPECTROSCOPY; LIQUID CARBON-MONOXIDE; NITROGEN; MIXTURES; TEMPERATURES; OXYGEN AB Recent technical advances have made it possible to obtain very useful spectroscopic information about simple molecules at temperatures and pressures exceeding 2000K and 10 GPa inside a diamond-anvil cell, which is well above any melting point for such systems. This is accomplished by obtaining vibrational spectra via Coherent Anti-Stokes Raman Spectroscopy in conjunction with CW laser heating using a tungsten toroid as a laser target. By the simultaneous use of these techniques, vibrational spectra with relatively high signal to noise can be obtained despite the enormous thermal background generated by the incandescence of extremely hot laser heated material. Temperatures can be measured. not only by fitting the Planck radiation to a graybody, but by the spectroscopic evidence of a Boltzmann distribution of molecules in their vibrationally excited quantum levels. Additionally, this technique allows for obtaining data at pressures and temperatures outside the region between the shock hugoniot and iseritrope, complementing shock wave experiments. C1 Lawrence Livermore Natl Lab, H Div, Livermore, CA 94566 USA. RP Baer, BJ (reprint author), Lawrence Livermore Natl Lab, H Div, Livermore, CA 94566 USA. EM baer4@llnl.gov; yoo1@llnl.gov NR 10 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1249 EP 1252 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000292 ER PT S AU Greenfield, SR Swift, DC Koskelo, AC AF Greenfield, SR Swift, DC Koskelo, AC BE Furnish, MD Gupta, YM Forbes, JW TI Transient interferometric studies of shocked bicrystals SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We have used a full-field displacement interferometry technique known as Transient Interferometric Microscopy (TIM) to generate displacement maps of surface motion at several delay times for single dynamic loading events. The high lateral resolution and out-of-plane displacement sensitivity allow the rich details of the motion of a single grain relative to the surrounding material to be quantitatively measured. Simultaneous line VISAR measurements allow detailed understanding of the complex surface motion. C1 Los Alamos Natl Lab, Adv Diagnost & Instrumentat Grp, Div Chem, Los Alamos, NM 87545 USA. RP Greenfield, SR (reprint author), Los Alamos Natl Lab, Adv Diagnost & Instrumentat Grp, Div Chem, POB 1663, Los Alamos, NM 87545 USA. EM greenfield@lanl.gov; dswift@lanl.gov; koskelo@lanl.gov NR 4 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1269 EP 1272 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000297 ER PT S AU Moore, DS McGrane, SD Funk, DJ AF Moore, DS McGrane, SD Funk, DJ BE Furnish, MD Gupta, YM Forbes, JW TI Ultrafast spectroscopic investigation of shock compressed energetic polymer films SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID WAVES AB Using ultrafast infrared absorption spectroscopy, we have observed shock induced changes to the vibrational spectra of nitrocellulose and polyvinyl nitrate films with similar to10 ps time resolution. The ca. 1 mum thin energetic polymer films were spin cast onto a thin (ca. 1 mum) aluminum shock driving layer, which had been vapor deposited onto a transparent substrate. A temporally-shaped ultrafast laser pulse was used to drive sustained shocks (10-20 ps rise, similar to200 ps at constant pressure) via laser ablation at the substrate/aluminum interface. The ultrafast infrared probing pulses, produced by optical parametric amplification and difference frequency generation techniques, provided similar to250 cm(-1) coverage at similar to150 fs pulse length. The IR probe was split into reference and sample beams. The sample beam was reflected through the shocked energetic material, and both sample and reference beams were focused onto the slit of a small imaging IR spectrometer and then detected using a HgCdTe focal plane array. Reference spectra were used to normalize the sample absorption spectrum. Time-resolved changes of the absorption spectra were obtained by stepping the shock drive/probe time delay. C1 Los Alamos Natl Lab, Mat Dynam Grp, Los Alamos, NM 87545 USA. RP Moore, DS (reprint author), Los Alamos Natl Lab, Mat Dynam Grp, MS P952, Los Alamos, NM 87545 USA. EM moored@lanl.gov; mcgrane@lanl.gov; djf@lanl.gov RI Moore, David/C-8692-2013 NR 9 TC 3 Z9 3 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1285 EP 1288 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000301 ER PT S AU Partouche-Sebban, D Pelissier, JL Anderson, WW Hixson, RS Holtkamp, DB AF Partouche-Sebban, D Pelissier, JL Anderson, WW Hixson, RS Holtkamp, DB BE Furnish, MD Gupta, YM Forbes, JW TI Characterization of sapphire for optical pyrometry in shock experiments SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID MODEL-POTENTIAL APPROACH; KBAR; WAVE AB Pyrometry measurements on shock-heated metals are often performed through a transparent anvil. Sapphire is an interesting anvil, but is also known to emit light when shocked above its Hugoniot Elastic Limit (HEL). To study its optical response, we have carried out experiments in the 15-37 GPa pressure range on c-cut sapphire in contact with a metallic sample (tin or bismuth) or a lithium fluoride window. Even though a significant amount of light is emitted by sapphire, we notice that the signal rise is directly related to the volume of sapphire under shock-loading. Consequently, the, window emission can be subtracted to infer the thermal radiation originating from the metal under study. A theoretical calculation of the expected pyrometer signals supports that point of view. These results give evidence that sapphire, despite its shock-induced optical emission above the HEL, can be used as a transparent anvil for quantitative pyrometry measurements at medium and high shock pressures. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Partouche-Sebban, D (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM dmps@lanl.gov; hixson@lanl.gov; holtkamp@lanl.gov NR 16 TC 1 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1289 EP 1292 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000302 ER PT S AU Partouche-Sebban, D AF Partouche-Sebban, D BE Furnish, MD Gupta, YM Forbes, JW TI High speed multi-wavelength pyrometry and emissivity measurement of shocked metals SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB In most shock experiments, the sample temperature needs to be measured in less than a microsecond. Currently, high-speed optical pyrometry seems to be the best way to perform this measurement. This is a challenge for any metal, particularly so at low shock pressures and for temperatures below 1000 K since, in this case, thermal flux is mostly emitted in the infrared spectrum where metal emissivities are generally low. An example of an optimized experimental design is presented, in which the strong optical background generally present in such experiments is eliminated. Moreover, when studying metals, pyrometry accuracy is mainly limited by the fact that the emissivity of the shock-loaded sample is not known accurately. As a result, we show how a careful choice of pyrometer wavelengths can minimize the effect of emissivity uncertainty. Finally, a recently developed technique based on integrated reflectometry allows measuring the sample surface emissivity during the experiment. It leads to a significant improvement on temperature accuracy and can be a means to detect phase transitions. Results on bismuth and tin are presented. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Partouche-Sebban, D (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM dmps@lanl.gov NR 13 TC 6 Z9 6 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1293 EP 1298 PG 6 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000303 ER PT S AU Bessette, GC Lawrence, RJ Chhabildas, LC Reinhart, WD Thornhill, TF Saul, WV AF Bessette, GC Lawrence, RJ Chhabildas, LC Reinhart, WD Thornhill, TF Saul, WV BE Furnish, MD Gupta, YM Forbes, JW TI Multi-dimensional hydrocode analyses of penetrating hypervelocity impacts SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The Eulerian hydrocode, CTH, has been used to study the interaction of hypervelocity flyer plates with thin targets at velocities from 6 to 11km/s. These penetrating impacts produce debris clouds that are subsequently allowed to stagnate against downstream witness plates. Velocity histories from this latter plate are used to infer the evolution and propagation of the debris cloud. This analysis, which is a companion to a parallel experimental effort, examined both numerical and physics-based issues. We conclude that numerical resolution and convergence are important in ways we had not anticipated. The calculated release from the extreme states generated by the initial impact shows discrepancies with related experimental observations, and indicates that even for well-known materials (e.g., aluminum), high-temperature failure criteria are not well understood, and that non-equilibrium or rate-dependent equations of state may be influencing the results. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bessette, GC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM lechhab@sandia.gov; tfthornm@sandia.gov NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1323 EP 1326 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000309 ER PT S AU Hoffman, NM Swift, DC AF Hoffman, NM Swift, DC BE Furnish, MD Gupta, YM Forbes, JW TI Predictions of the microstructural contribution to instability seeding in beryllium ICF capsules SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The constitutive properties of beryllium are anisotropic. During the implosion of an inertial confinement fusion capsule, it is possible for instabilities to be seeded from the microstructure. We are using experiment and theory to place constraints on the microstructure and loading history. The relation between surface roughness and amplitude of ablative Rayleigh-Taylor instabilities has been characterized well. Here we present a method of relating the microstructure to an equivalent surface roughness, using continuum mechanical simulations of shock waves in poly-crystalline beryllium. Beryllium was treated using a single-crystal plasticity model developed using ab initio quantum mechanics for the equation of state and elasticity, and laser-driven shock wave measurements to calibrate representations of dislocation and disclination dynamics. C1 Los Alamos Natl Lab, Appl Plasma Phys X1, Los Alamos, NM 87545 USA. RP Hoffman, NM (reprint author), Los Alamos Natl Lab, Appl Plasma Phys X1, Los Alamos, NM 87545 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1339 EP 1342 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000313 ER PT S AU Rodriguez, G Roberts, JP Taylor, AJ AF Rodriguez, G Roberts, JP Taylor, AJ BE Furnish, MD Gupta, YM Forbes, JW TI Electromagnetically-driven cylindrical 2-D shockwave profile measurements in water with laser shadowgraphy SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Experiments performed at the Los Alamos National Laboratory's Atlas 23 MJ z-pinch capacitor bank facility allows for experimental characterization of electro-magnetically driven cylindrical shockwave implosions. Time resolved laser shadowgraphy is used to dynamically image an Atlas generated liner-target radial shock implosion in water with 2-D imaging detail that provides benchmark results for numerical hydro-code validation efforts at Los Alamos. Theoretical interest in these shock experiments arises since the shock propagation velocity is modified as shock-strengthening effects are predicted to occur as material flow approaches the region of on-axis convergence. Our laser shadowgraph measurements capture eight separate image frames of shockwave motion in the water with an overall spatial and temporal resolution of +/-0.25 mm and 10 ns, respectively. Imaging of the shockwave radial shape and position inside the water volume allows for quantitative comparison with numerical simulations. A linear fit to the average radius 1-D shockwave trajectory plot yields a shock speed in the water of 6.65 mm/mus corresponding to a Mach 4 shock. Comparison of the measured shockwave trajectory with the numerical hydrodynamic simulation codes is performed. C1 Condensed Matter & Thermal Phys Grp, Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rodriguez, G (reprint author), Condensed Matter & Thermal Phys Grp, Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM rodrigeo@lanl.gov RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1351 EP 1354 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000316 ER PT S AU Gammel, JT Swift, D Tierney, T AF Gammel, JT Swift, D Tierney, T BE Furnish, MD Gupta, YM Forbes, JW TI Shock response of iron on nanosecond time scales SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Experiments were performed using direct laser irradiation to induce shock waves in pure Fe foils tens of microns thick, using surface velocimetry to measure the response. Compared with experiments on much thicker samples, relatively strong elastic precursors were observed, though these could be caused by the strong texture of the foils rather than the shorter time scale. There was also evidence for the onset of the bcc to hcp phase transition, starting close to the static phase boundary. Radiation hydrodynamics and continuum mechanical simulations were performed to interpret the velocity data, comparing several equations of state with polymorphism and strength. The data were consistent with a phase change rate of the order of 10(9)/s, driven by superpressurization of about 5 GPa. The rate may also depend on texture. C1 Los Alamos Natl Lab, Equat State T1, Los Alamos, NM 87545 USA. RP Gammel, JT (reprint author), Los Alamos Natl Lab, Equat State T1, Los Alamos, NM 87545 USA. EM jtg@lanl.gov; dswift@lanl.gov; tomt@lanl.gov NR 8 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1385 EP 1388 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000324 ER PT S AU Rodriguez, G Clarke, SA Taylor, AJ Forsman, A AF Rodriguez, G Clarke, SA Taylor, AJ Forsman, A BE Furnish, MD Gupta, YM Forbes, JW TI Diagnosis of ultrafast laser-heated metal surfaces and plasma expansion with absolute displacement interferometry SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We report on the development of a novel technique to measure the critical surface displacement in intense, ultrashort, laser-solid target experiments. Determination of the critical surface position is important for understanding near solid density plasma dynamics and transport from warm dense matter systems, and for diagnosing short scale length plasma expansion and hydrodynamic surface motion from short pulse, laser-heated, solid targets. Instead of inferring critical surface motion from spectral power shifts using a time-delayed probe pulse or from phase shifts using ultrafast pump-probe frequency domain interferometry (FDI), this technique directly measures surface displacement using a single ultrafast laser heating pulse. Our technique is based on an application of a Michelson Stellar interferometer to microscopic rather than stellar scales, and we report plasma scale length motion as small as 10 nm. We will present results for motion of plasmas generated from several target materials (Au, Al, Au on CH plastic) for a laser pulse intensity range from 10(11) to 10(16) W/cm(2). Varying both, the pulse duration and the pulse energy, explores the dependence of the expansion mechanism on the energy deposited and on the peak intensity. Comparisons with hydrocodes reveal the applicability of hydrodynamic models. C1 Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Rodriguez, G (reprint author), Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. EM rodrigeo@lanl.gov RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 4 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1401 EP 1404 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000328 ER PT S AU Schmitt, MJ Kopp, RA Moore, DS McGrane, SD AF Schmitt, MJ Kopp, RA Moore, DS McGrane, SD BE Furnish, MD Gupta, YM Forbes, JW TI Analysis of laser-driven shocks in confined and unconfined geometries SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Pulsed lasers are convenient generators of shocks in materials. The efficacy of laser shock generation depends on several factors including laser-target coupling, laser pulse temporal shape and intensity, and the resultant pressure profile generated at the target surface. Target coupling is a dynamic mechanism that changes as the target surface evolves due to heating, ionization and ablation during laser irradiation. Confining a metal target surface using a transparent "tamper" material can increase the impulse transferred to the target, but also can cause decoupling of the laser energy from the target as the heated tamper begins to move the laser absorption region away from the metal surface. We have analyzed this process using the radiation hydrodynamics code Lasnex in an attempt to simulate experiments using planar targets and determine the coupling efficiency versus tamper material properties. Good agreement with experimental measurements of the shock pressure in Al and PMMA were obtain using laser absorption values of 40%. Dielectric tamping of the laser absorption increased the shock pressures by factors of 2 to 3. Further increases in pressure into the megabar regime were obtained inside the tamping dielectric as a radiatively-coupled ionization wave propagated back toward the laser. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Schmitt, MJ (reprint author), Los Alamos Natl Lab, MS B259, Los Alamos, NM 87545 USA. EM mjs@lanl.gov; moored@lanl.gov; mcgrane@lanl.gov RI Moore, David/C-8692-2013 NR 5 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1409 EP 1412 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000330 ER PT S AU Tierney, TE Swift, DC Johnson, RP AF Tierney, TE Swift, DC Johnson, RP BE Furnish, MD Gupta, YM Forbes, JW TI Novel techniques for laser-irradiatioin driven, dynamic materials experiments SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp ID COMPRESSION AB Dynamic loading experiments are described using nanosecond scale laser pulses of 2 to 1000 GW/cm(2) over a region 5 mm in diameter. The laser irradiance was tailored to generate shocks or quasi-isentropic compression. The experiments include novel diagnostic techniques with high temporal resolution: transient x-ray diffraction (TXD) and polarization-dependent reflectivity (ellipsometry). TXD uses a laser-produced plasma to form an x-ray source. These x rays are collimated by a pinhole to form a Bragg scattering source, which allowed powder lines to be detected from polycrystalline samples such as beryllium foils. Ellipsometry has been demonstrated with 50 ps resolution using the reflectance of a pulsed 660 nm laser from silicon and tin samples through lithium fluoride windows. Ellipsometry can indicate phase changes and potentially yields estimates of surface temperature via the dielectric conductivity. The combination of TXD and ellipsometry with VISAR measurements provides precision characterization of dynamic material properties at high pressures. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tierney, TE (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM tomt@lanl.gov; dswift@lanl.gov NR 9 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1413 EP 1416 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000331 ER PT S AU Antoun, TH Lomov, IN AF Antoun, TH Lomov, IN BE Furnish, MD Gupta, YM Forbes, JW TI Simulation of a spherical wave experiment in marble using a multidirectional damage model SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB This paper presents experimental results and computational simulations of spherical wave propagation in Danby marble. The experiment consisted of a 2-cm-diameter explosive charge detonated in the center of a cylindrical rock sample. Radial particle velocity histories were recorded at several concentric locations in the sample. An extensively damaged region near the charge cavity and two networks of cracks were evident in the specimen after the test. The first network consists of radial cracks emanating form the cavity and extending about halfway through the specimen. The second network consists of circumferential cracks occurring in a relatively narrow band that extends from the outer boundary of the radially cracked region toward the free surface. The experiment was simulated using the GEODYN code and a multi-directional damage model. The model is developed within the framework of a properly invariant nonlinear thermomechanical theory with damage represented by a second order tensor that admits load-induced anisotropy such as was observed in the experiment. C1 Lawrence Livermore Natl Lab, Div Earth Sci, Livermore, CA 94551 USA. RP Antoun, TH (reprint author), Lawrence Livermore Natl Lab, Div Earth Sci, Livermore, CA 94551 USA. EM antoun1@llnl.gov; lomov1@llnl.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1423 EP 1426 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000333 ER PT S AU Lomov, IN Antoun, TH Wagoner, J Rambo, JT AF Lomov, IN Antoun, TH Wagoner, J Rambo, JT BE Furnish, MD Gupta, YM Forbes, JW TI Three dimensional simulation of the Baneberry nuclear event SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB Baneberry, a 10-kiloton nuclear event, was detonated at a depth of 278 m at the Nevada Test Site on December 18, 1970. Shortly after detonation, radioactive gases emanating from the cavity were released into the atmosphere through a shock-induced fissure near surface ground zero. Extensive geophysical investigations, coupled with a series of 1D and 2D computational studies were used to reconstruct the sequence of events that led to the catastrophic failure. However, the geological profile of the Baneberry site is complex and inherently three-dimensional, which meant that some geological features had to be simplified or ignored in the 2D simulations. This left open the possibility that features unaccounted for in the 2D simulations could have had an important influence on the eventual containment failure of the Baneberry event. This paper presents results from a high-fidelity 3D Baneberry simulation based on the most accurate geologic and geophysical data available. The results are compared with available data, and contrasted against the results of the previous 2D computational studies. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lomov, IN (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. EM lomov1@llnl.gov; antoun1@llnl.gov NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1462 EP 1465 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000342 ER PT S AU Morris, JP Glenn, LA Heuze, FE Bonner, MP AF Morris, JP Glenn, LA Heuze, FE Bonner, MP BE Furnish, MD Gupta, YM Forbes, JW TI Simulations of underground structures subjected to dynamic loading using the distinct element method SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB We present preliminary results from a parameter study investigating the stability of underground structures in response to explosion-induced strong ground motions. In practice, even the most sophisticated site characterization may lack key details regarding precise joint properties and orientations within the rock mass. Thus, in order to place bounds upon the predicted behavior of a given facility, an extensive series of simulations representing different realizations may be required. The influence of both construction parameters (reinforcement, rock bolts,liners) and geological parameters (joint stiffness, joint spacing and orientation, and tunnel diameter to block size ratio) must be considered. We will discuss the distinct element method (DEM) with particular emphasis on techniques for achieving improved computational efficiency, including the handling of contact detection and approaches to parallelization. We also outline the continuum approaches we employ to obtain boundary conditions for the distinct element simulations. Finally, our DEM code is used to simulate dynamic loading of a generic subterranean facility in hardrock, demonstrating the suitability of the DEM for this application. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Morris, JP (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. EM lewglenn@llnl.gov NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1470 EP 1473 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000344 ER PT S AU Kennedy, J Plaksin, I Thomas, K Martin, E Lee, KY Akinci, A Asay, B Campos, J Direito, J AF Kennedy, J Plaksin, I Thomas, K Martin, E Lee, KY Akinci, A Asay, B Campos, J Direito, J BE Furnish, MD Gupta, YM Forbes, JW TI Instrumented floret tests of detonation spreading SO SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS SE AIP Conference Proceedings LA English DT Proceedings Paper CT 13th Conference of the American-Physical-Society-Topical-Group on Shock Compression of Condensed Matter CY JUL 20-25, 2003 CL Portland, OR SP Amer Phys Soc Top Grp AB The floret test was originally devised to permit comparison of detonation-spreading performance of various insensitive explosive materials, using only the dent in a copper witness plate as a metric. Dent depth in the copper plate is directly related to the fraction of a thin acceptor pellet that was detonated by impact of a small explosive-driven flyer plate. We have now added instrumentation to quantitatively measure the detonation corner-turning behavior of IHEs. Results of multi-fiber optical probe measurements are shown for LLM-105 and UF-TATB explosive materials. Results are interpreted and compared with predictions from one reaction-rate model used to describe detonation spreading, and may be advantageous for comparison with other reactive-flow wave-code models. Detonation spreading in UF-TATB occurred with formation of a non-detonating region surrounding a detonating core, and re-establishment of detonation in a "lateral" direction beyond that region. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kennedy, J (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. EM jkennedy@lanl.gov; bwa@lanl.gov; ledapc@mail.telepac.pt NR 6 TC 1 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0181-0 J9 AIP CONF PROC PY 2004 VL 706 BP 1500 EP 1503 PG 4 WC Materials Science, Multidisciplinary; Mechanics; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA BAT26 UT WOS:000223423000351 ER PT J AU Bou-Rabee, NM Marsden, JE Romero, LA AF Bou-Rabee, NM Marsden, JE Romero, LA TI Tippe top inversion as a dissipation-induced instability SO SIAM JOURNAL ON APPLIED DYNAMICAL SYSTEMS LA English DT Article DE tippe top inversion; dissipation-induced instability; constrained rotational motion; axisymmetric rigid body AB By treating tippe top inversion as a dissipation-induced instability, we explain tippe top inversion through a system we call the modified Maxwell-Bloch equations. We revisit previous work done on this problem and follow Or's mathematical model [ SIAM J. Appl. Math., 54 ( 1994), pp. 597-609]. A linear analysis of the equations of motion reveals that the only equilibrium points correspond to the inverted and noninverted states of the tippe top and that the modified Maxwell-Bloch equations describe the linear/spectral stability of these equilibria. We supply explicit criteria for the spectral stability of these states. A nonlinear global analysis based on energetics yields explicit criteria for the existence of a heteroclinic connection between the noninverted and inverted states of the tippe top. This criteria for the existence of a heteroclinic connection turns out to agree with the criteria for spectral stability of the inverted and noninverted states. Throughout the work we support the analysis with numerical evidence and include simulations to illustrate the nonlinear dynamics of the tippe top. C1 CALTECH, Pasadena, CA 91125 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bou-Rabee, NM (reprint author), CALTECH, Pasadena, CA 91125 USA. EM nawaf@acm.caltech.edu; marsden@cds.caltech.edu; lromero@sandia.gov NR 14 TC 32 Z9 34 U1 1 U2 6 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1536-0040 J9 SIAM J APPL DYN SYST JI SIAM J. Appl. Dyn. Syst. PY 2004 VL 3 IS 3 BP 352 EP 377 DI 10.1137/030601351 PG 26 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 871CT UT WOS:000225107600004 ER PT J AU Li, J Zhou, YC Ma, Z Hyman, JM AF Li, J Zhou, YC Ma, Z Hyman, JM TI Epidemiological models for mutating pathogens SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE epidemic model; pathogen; mutation; infection age; reproductive number; global stability; Hopf bifurcation ID INFLUENZA-A DRIFT; HETEROGENEOUS POPULATIONS; INFECTIOUS-DISEASES; VIRUS-STRAINS; THRESHOLD; HEPATITIS; EVOLUTION; DYNAMICS; SPREAD AB We formulate epidemiological models for the transmission of a pathogen that can mutate in the host to create a second infectious mutant strain. The models account for mutation rates that depend on how long the host has been infected. We derive explicit formulas for the reproductive number of the epidemic based on the local stability of the infection-free equilibrium. We analyze the existence and stability of the boundary equilibrium, whose infection components are zero and positive, respectively, and the endemic equilibrium, whose components are all positive. We establish the conditions for global stability of the infection-free and boundary equilibria and local stability of the endemic equilibrium for the case where there is no age structure for the pathogen in the infected population. We show that under certain circumstances, there is a Hopf bifurcation where the endemic equilibrium loses its stability, and periodic solutions appear. We provide examples and numerical simulations to illustrate the Hopf bifurcation. C1 Univ Alabama, Dept Math Sci, Huntsville, AL 35899 USA. Xian Jiaotong Univ, Dept Appl Math, Xian 710049, Peoples R China. Los Alamos Natl Lab, Ctr Nonlinear Studies, Energy Program Theoret Div, Los Alamos, NM 87545 USA. RP Zhou, YC (reprint author), Univ Alabama, Dept Math Sci, Huntsville, AL 35899 USA. EM li@math.uah.edu; zhouyc@mail.xjtu.edu.cn; zhma@xjtu.edu.cn; hyman@lanl.gov NR 24 TC 22 Z9 33 U1 0 U2 5 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2004 VL 65 IS 1 BP 1 EP 23 DI 10.1137/S0036139903430185 PG 23 WC Mathematics, Applied SC Mathematics GA 881RR UT WOS:000225887600001 ER PT J AU Hald, OH Shestakov, AI AF Hald, OH Shestakov, AI TI Stability of stationary solutions of the multifrequency radiation diffusion equations SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE stationary solutions; multifrequency radiation diffusion AB A nondimensional model of the multifrequency radiation diffusion equation is derived. A single material ideal gas equation-of-state is assumed. Opacities are proportional to the inverse of the cube of the frequency. Inclusion of stimulated emission implies a Wien spectrum for the radiation source function. It is shown that the solutions are uniformly bounded in time and that stationary solutions are stable. The spatially independent solutions are asymptotically stable, while the spatially dependent solutions of the linearized equations approach zero. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Hald, OH (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. EM hald@math.berkeley.edu; shestakov@llnl.gov NR 12 TC 1 Z9 1 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2004 VL 65 IS 1 BP 175 EP 193 DI 10.1137/S0036139902407303 PG 19 WC Mathematics, Applied SC Mathematics GA 881RR UT WOS:000225887600009 ER PT J AU Wilkening, J Borucki, L Sethian, JA AF Wilkening, J Borucki, L Sethian, JA TI Analysis of stress-driven grain boundary diffusion. Part I SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE grain boundary; diffusion; electromigration; elasticity; semigroups ID ELECTROMIGRATION; LINES; EVOLUTION; CIRCUITS AB The stress-driven grain boundary diffusion problem is a continuum model of mass transport phenomena in microelectronic circuits due to high current densities (electromigration) and gradients in normal stress along grain boundaries. The model involves coupling many different equations and phenomena, and difficulties such as nonlocality, complex geometry, and singularities in the stress tensor have left open such mathematical questions as existence of solutions and compatibility of boundary conditions. In this paper and its companion, we address these issues and establish a firm mathematical foundation for this problem. We use techniques from semigroup theory to prove that the problem is well posed and that the stress field relaxes to a steady state distribution which, in the nondegenerate case, balances the electromigration force along grain boundaries. Our analysis shows that while the role of electromigration is important, it is the interplay among grain growth, stress generation, and mass transport that is responsible for the diffusive nature of the problem. Electromigration acts as a passive driving force that determines the steady state stress distribution, but it is not responsible for the dynamics that drive the system to steady state. We also show that stress singularities may develop near grain boundary junctions; however, stress components directly involved in the diffusion process remain finite for all time. Thus, we have identified a mechanism by which large "hidden" stresses may develop that are not directly involved in the diffusion process but may play a role in void nucleation and stress-induced damage. C1 NYU, Courant Inst Math Sci, New York, NY 10012 USA. Motorola Inc, Tempe, AZ 85284 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94721 USA. RP Wilkening, J (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. EM wilken@cims.nyu.edu; Len.Borucki@intelligentplanar.com; sethian@math.berkeley.edu NR 33 TC 6 Z9 6 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2004 VL 64 IS 6 BP 1839 EP 1863 PG 25 WC Mathematics, Applied SC Mathematics GA 857MW UT WOS:000224122400001 ER PT J AU Wilkening, J Borucki, L Sethian, JA AF Wilkening, J Borucki, L Sethian, JA TI Analysis of stress-driven grain boundary diffusion. Part II: Degeneracy SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE grain boundary; diffusion; electromigration; elasticity; semigroups AB The stress-driven grain boundary diffusion problem is a continuum model of mass transport phenomena in microelectronic circuits due to high current densities (electromigration) and gradients in normal stress along grain boundaries. The model involves coupling many different equations and phenomena, and difficulties such as nonlocality, complex geometry, and singularities in the stress tensor have left open such mathematical questions as existence of solutions and compatibility of boundary conditions. In this paper and its companion, we address these issues and establish a firm mathematical foundation for this problem. We study the properties of a type of Dirichlet-to-Neumann map that involves solving the Lame equations with interesting interface boundary conditions. We identify a new class of degenerate grain boundary networks that lead to unsuppressed linear growth modes that are suggestive of continental drift in plate tectonics. We use techniques from semigroup theory to prove that the problem is well posed and that the stress field relaxes to a steady state distribution which may or may not completely balance the electromigration force. In the latter (degenerate) case, the displacements continue to grow without bound along stress-free modes. C1 NYU, Courant Inst Math Sci, New York, NY 10012 USA. Motorola Inc, Tempe, AZ 85284 USA. Univ Calif Berkeley, Dept Math, Berkeley, CA 94721 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94721 USA. RP Wilkening, J (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. EM wilken@cims.nyu.edu; LenBorucki@intelligentplanar.com; sethian@math.berkeley.edu NR 14 TC 5 Z9 5 U1 1 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2004 VL 64 IS 6 BP 1864 EP 1886 DI 10.1137/S0036139903438247 PG 23 WC Mathematics, Applied SC Mathematics GA 857MW UT WOS:000224122400002 ER PT J AU Miller, GH AF Miller, GH TI Minimal rotationally invariant bases for hyperelasticity SO SIAM JOURNAL ON APPLIED MATHEMATICS LA English DT Article DE elasticity; hyperelasticity; symmetry; integrity basis; Grobner bases ID COMPUTING GROBNER BASES; ALGORITHM; TENSORS; ORDER AB Rotationally invariant polynomial bases of the hyperelastic strain energy function are rederived using methods of group theory, invariant theory, and computational algebra. A set of minimal basis functions is given for each of the 11 Laue groups, with a complete set of rewriting syzygies. The ideal generated from this minimal basis agrees with the classic work of Smith and Rivlin [Trans. Amer. Math. Soc., 88 (1958), pp. 175-193]. However, the structure of the invariant algebra described here calls for fewer terms, beginning with the fourth degree in strain, for most groups. C1 Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Appl Numer Algorithms Grp, Berkeley, CA 94720 USA. RP Miller, GH (reprint author), Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. EM grgmiller@ucdavis.edu NR 25 TC 3 Z9 3 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1399 J9 SIAM J APPL MATH JI SIAM J. Appl. Math. PY 2004 VL 64 IS 6 BP 2050 EP 2075 DI 10.1137/S0036139903438776 PG 26 WC Mathematics, Applied SC Mathematics GA 857MW UT WOS:000224122400010 ER PT J AU Lee, B McCormick, SF Philip, B Quinlan, DJ AF Lee, B McCormick, SF Philip, B Quinlan, DJ TI Asynchronous fast adaptive composite-grid methods for elliptic problems: Theoretical foundations SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE adaptive mesh refinement; asynchronous; fast adaptive composite-grid; elliptic solvers; FAC; AFAC; AFACx ID PARTIAL-DIFFERENTIAL EQUATIONS; MULTIGRID ALGORITHMS; MULTILEVEL; MULTIPROCESSORS; FAC AB Accurate numerical modeling of complex physical, chemical, and biological systems requires numerical simulation capability over a large range of length scales, with the ability to capture rapidly varying phenomena localized in space and/or time. Adaptive mesh refinement (AMR) is a numerical process for dynamically introducing local. ne resolution on computational grids during the solution process, in response to unresolved error in a computation. Fast adaptive composite-grid (FAC) methods are a class of algorithms that exploit the multilevel structure of AMR grids to solve elliptic problems efficiently. This paper develops a theoretical foundation for AFACx, an asynchronous FAC method. A new multilevel condition number estimate establishes that the convergence rate of the AFACx algorithm does not degrade as the number of refinement levels in the AMR hierarchy increases. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. EM lee123@llnl.gov; stevem@newton.colorado.edu; bphilip@lanl.gov; dquinlan@llnl.gov OI Philip, Bobby/0000-0001-6716-3515 NR 50 TC 4 Z9 4 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 EI 1095-7170 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2004 VL 42 IS 1 BP 130 EP 152 DI 10.1137/S0036142902400767 PG 23 WC Mathematics, Applied SC Mathematics GA 802WJ UT WOS:000220193300007 ER PT J AU Cai, ZQ Lee, B Wang, P AF Cai, ZQ Lee, B Wang, P TI Least-squares methods for incompressible Newtonian fluid flow: Linear stationary problems SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE least-squares method; mixed finite element method; Navier-Stokes; Stokes; incompressible Newtonian flow ID FINITE-ELEMENT METHODS; ONE INNER-PRODUCT; STOKES EQUATIONS; FORMULATION; ELASTICITY AB This paper develops and analyzes two least-squares methods for the numerical solution of linear, stationary incompressible Newtonian fluid flow in two and three dimensions. Both approaches use the L-2 norm to define least-squares functionals. One is based on the stress-velocity formulation (see section 3.2), and it applies to general boundary conditions. The other is based on an equivalent formulation for the pseudostress and velocity (see section 4.2), and it applies to pure velocity Dirichlet boundary conditions. The velocity gradient and vorticity can be obtained algebraically from this new tensor variable. It is shown that the homogeneous least-squares functionals are elliptic and continuous in the H(div; Omega)(d) x H-1(Omega)(d) norm. This immediately implies optimal error estimates for conforming finite element approximations. As well, it admits optimal multigrid solution methods if Raviart-Thomas finite element spaces are used to approximate the stress or the pseudostress tensor. C1 Purdue Univ, Dept Math, W Lafayette, IN 47907 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Lawrence Livermore Natl Lab, DNT Comp Applicat Div, Livermore, CA 94551 USA. RP Cai, ZQ (reprint author), Purdue Univ, Dept Math, 150 N Univ St, W Lafayette, IN 47907 USA. EM zcai@math.purdue.edu; lee123@llnl.gov; wang32@llnl.gov NR 24 TC 43 Z9 43 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2004 VL 42 IS 2 BP 843 EP 859 DI 10.1137/S0036142903422673 PG 17 WC Mathematics, Applied SC Mathematics GA 839HD UT WOS:000222773600017 ER PT J AU Bochev, P Gunzburger, M AF Bochev, P Gunzburger, M TI An absolutely stable pressure-Poisson stabilized finite element method for the Stokes equations SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE stabilized finite element methods; mixed methods; Stokes problem ID COMPUTATIONAL FLUID-DYNAMICS; LEAST-SQUARES METHODS; FORMULATION AB The pressure-Poisson stabilized Galerkin method for the Stokes equation requires the choice of a positive parameter. Existing theoretical predictions for the range of parameter values that yield stable discretizations seem to be very pessimistic when compared to the computational evidence. Motivated by this wide gap, we first examine a continuous prototype for this class of schemes. We show that the prototype is absolutely stable; i.e., it is stable for all parameter values, and is optimally accurate. We then de. ne a new, practical variant of the well-known pressure-Poisson stabilized scheme. We prove that the new method is absolutely stable just like its continuous prototype and that it achieves optimal convergence rates with respect to the same mesh-independent norms. The new method differs from the standard pressure-Poisson stabilized method in several important aspects. First, its definition does not degrade to a penalty formulation for the lowest order nodal spaces. Second, the method is absolutely stable with respect to the natural norm for the problem, while the standard pressure-Poisson stabilized method is stable with respect to a mesh-dependent norm. C1 Sandia Natl Labs, Computat Math & Algorithms Dept, Albuquerque, NM 87185 USA. Florida State Univ, Sch Computat Sci & Informat Technol, Tallahassee, FL 32306 USA. RP Bochev, P (reprint author), Sandia Natl Labs, Computat Math & Algorithms Dept, POB 5800, Albuquerque, NM 87185 USA. EM pbboche@sandia.gov; gunzburg@csit.fsu.edu NR 19 TC 42 Z9 47 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2004 VL 42 IS 3 BP 1189 EP 1207 DI 10.1137/S0036142903416547 PG 19 WC Mathematics, Applied SC Mathematics GA 881RQ UT WOS:000225887500016 ER PT J AU Kreiss, HO Petersson, NA Ystrom, J AF Kreiss, HO Petersson, NA Ystrom, J TI Difference approximations of the Neumann problem for the second order wave equation SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE wave equation; stability; accuracy; embedded boundary ID BOUNDARY; STABILITY; FLOW AB Stability theory and numerical experiments are presented for a finite difference method that directly discretizes the Neumann problem for the second order wave equation. Complex geometries are discretized using a Cartesian embedded boundary technique. Both second and third order accurate approximations of the boundary conditions are presented. Away from the boundary, the basic second order method can be corrected to achieve fourth order spatial accuracy. To integrate in time, we present both a second order and a fourth order accurate explicit method. The stability of the method is ensured by adding a small fourth order dissipation operator, locally modified near the boundary to allow its application at all grid points inside the computational domain. Numerical experiments demonstrate the accuracy and long-time stability of the proposed method. C1 Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90024 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. Royal Inst Technol, Dept Numer Anal & Comp Sci, S-10044 Stockholm, Sweden. RP Kreiss, HO (reprint author), Univ Calif Los Angeles, Dept Math, Los Angeles, CA 90024 USA. EM Kreiss@math.ucla.edu; andersp@llnl.gov; yxan@nada.kth.se NR 16 TC 32 Z9 32 U1 0 U2 5 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2004 VL 42 IS 3 BP 1292 EP 1323 DI 10.1137/S003614290342827X PG 32 WC Mathematics, Applied SC Mathematics GA 881RQ UT WOS:000225887500020 ER PT J AU Falgout, RD Vassilevski, PS AF Falgout, RD Vassilevski, PS TI On generalizing the algebraic multigrid framework SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE algebraic multigrid; compatible relaxation ID AMGE AB We present a theory for algebraic multigrid (AMG) methods that allows for general smoothing processes and general coarsening approaches. The goal of the theory is to provide guidance in the development of new, more robust, AMG algorithms. In particular, we introduce several compatible relaxation methods and give theoretical justification for their use as tools for measuring the quality of coarse grids. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94551 USA. RP Falgout, RD (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, POB 808, Livermore, CA 94551 USA. EM rfalgout@llnl.gov; panayot@llnl.gov NR 21 TC 56 Z9 58 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PY 2004 VL 42 IS 4 BP 1669 EP 1693 DI 10.1137/S0036142903429742 PG 25 WC Mathematics, Applied SC Mathematics GA 894XC UT WOS:000226823900015 ER PT J AU Gould, NIM Leyffer, S Toint, PL AF Gould, NIM Leyffer, S Toint, PL TI A multidimensional filter algorithm for nonlinear equations and nonlinear least-squares SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE nonlinear equations; nonlinear least-squares; nonlinear fitting; filter methods; trust-region algorithms ID UNCONSTRAINED TESTING ENVIRONMENT; TRUST-REGION ALGORITHMS; GLOBAL CONVERGENCE; OPTIMIZATION AB We introduce a new algorithm for the solution of systems of nonlinear equations and nonlinear least-squares problems that attempts to combine the efficiency of filter techniques and the robustness of trust-region methods. The algorithm is shown, under reasonable assumptions, to globally converge to zeros of the system, or to first-order stationary points of the Euclidean norm of its residual. Preliminary numerical experience is presented that shows substantial gains in efficiency over the traditional monotone trust-region approach. C1 Rutherford Appleton Lab, Computat Sci & Engn Dept, Chilton OX11 0QX, Oxon, England. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Namur, Dept Math, B-5000 Namur, Belgium. RP Gould, NIM (reprint author), Rutherford Appleton Lab, Computat Sci & Engn Dept, Chilton OX11 0QX, Oxon, England. EM n.gould@rl.ac.uk; leyffer@mcs.anl.gov; philippe.toint@fundp.ac.be OI Gould, Nicholas/0000-0002-1031-1588 NR 26 TC 52 Z9 56 U1 0 U2 4 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2004 VL 15 IS 1 BP 17 EP 38 DI 10.1137/S1052623403422637 PG 22 WC Mathematics, Applied SC Mathematics GA 883XI UT WOS:000226048600002 ER PT J AU Kolda, TG Torczon, VJ AF Kolda, TG Torczon, VJ TI On the convergence of asynchronous parallel pattern search SO SIAM JOURNAL ON OPTIMIZATION LA English DT Article DE asynchronous parallel optimization; pattern search; unconstrained optimization; global convergence analysis ID UNCONSTRAINED OPTIMIZATION; ALGORITHMS AB In this paper we prove global convergence for asynchronous parallel pattern search. In standard pattern search, decisions regarding the update of the iterate and the step-length control parameter are synchronized implicitly across all search directions. We lose this feature in asynchronous parallel pattern search since the search along each direction proceeds semiautonomously. By bounding the value of the step-length control parameter after any step that produces decrease along a single search direction, we can prove that all the processes share a common accumulation point and, if the function is continuously differentiable, that such a point is a stationary point of the standard nonlinear unconstrained optimization problem. C1 Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. Coll William & Mary, Dept Comp Sci, Williamsburg, VA 23187 USA. RP Kolda, TG (reprint author), Sandia Natl Labs, Computat Sci & Math Res Dept, Livermore, CA 94551 USA. EM tgkolda@sandia.gov; va@cs.wm.edu RI Kolda, Tamara/B-1628-2009 OI Kolda, Tamara/0000-0003-4176-2493 NR 11 TC 16 Z9 16 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1052-6234 J9 SIAM J OPTIMIZ JI SIAM J. Optim. PY 2004 VL 14 IS 4 BP 939 EP 964 DI 10.1137/S1052623401398107 PG 26 WC Mathematics, Applied SC Mathematics GA 860MZ UT WOS:000224349000001 ER PT J AU Gray, LJ Phan, AV Kaplan, T AF Gray, LJ Phan, AV Kaplan, T TI Boundary integral evaluation of surface derivatives SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE boundary integral method; surface derivatives; hypersingular integrals; boundary limit ID DISPLACEMENT DISCONTINUITY METHOD; HYPERSINGULAR INTEGRALS; ELEMENT METHOD; POTENTIAL GRADIENT; STRESS CALCULATION; FRACTURE-ANALYSIS; 3D BEM; EQUATIONS; GALERKIN; CRACK AB In boundary element analysis, first order function derivatives, e.g., boundary potential gradient or stress tensor, can be accurately computed by evaluating the hypersingular integral equation for these quantities. However, this approach requires a complete integration over the boundary and is therefore computationally quite expensive. Herein it is shown that this method can be significantly simplified: only local singular integrals need to be evaluated. The procedure is based upon de. ning the singular integrals as a limit to the boundary and exploiting the ability to use both interior and exterior boundary limits. Test calculations for two- and three-dimensional problems demonstrate the accuracy of the method. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Gray, LJ (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. EM ljg@ornl.gov; vphan@jaguar1.usouthal.edu; tsk@ornl.gov NR 54 TC 10 Z9 11 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 1 BP 294 EP 312 DI 10.1137/S1064827502406002 PG 19 WC Mathematics, Applied SC Mathematics GA 881RS UT WOS:000225887700014 ER PT J AU Le Maitre, O Reagan, MT Debusschere, B Najm, HN Ghanem, RG Knio, OM AF Le Maitre, O Reagan, MT Debusschere, B Najm, HN Ghanem, RG Knio, OM TI Natural convection in a closed cavity under stochastic non-Boussinesq conditions SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE stochastic; natural convection; Navier-Stokes; polynomial chaos; Karhunen-Loeve; uncertainty ID SEMIIMPLICIT NUMERICAL SCHEME; HERMITE EXPANSION; PROJECTION METHOD; REACTING FLOW; FLUID-FLOW; COMPUTATION; POLYNOMIALS; WIENER; NUMBER; STIFF AB A stochastic projection method (SPM) is developed for quantitative propagation of uncertainty in compressible zero-Mach-number flows. The formulation is based on a spectral representation of uncertainty using the polynomial chaos (PC) system, and on a Galerkin approach to determining the PC coefficients. Governing equations for the stochastic modes are solved using a mass-conservative projection method. The formulation incorporates a specially tailored stochastic inverse procedure for exactly satisfying the mass-conservation divergence constraints. A brief validation of the zero-Mach-number solver is first performed, based on simulations of natural convection in a closed cavity. The SPM is then applied to analyze the steady-state behavior of the heat transfer and of the velocity and temperature fields under stochastic non-Boussinesq conditions. C1 Univ Evry Val Essone, Ctr Etud Mecan Ile France, F-91020 Evry, France. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. Johns Hopkins Univ, Dept Civil Engn, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. RP Le Maitre, O (reprint author), Univ Evry Val Essone, Ctr Etud Mecan Ile France, 40 Rue Pelvoux, F-91020 Evry, France. EM olm@iup.univ-evry.fr; mtreaga@ca.sandia.gov; bjdebus@ca.sandia.gov; hnnajm@ca.sandia.gov; ghanem@jhu.edu; knio@jhu.edu RI Knio, Omar/A-3318-2010; Ghanem, Roger/B-8570-2008; Le Maitre, Olivier/D-8570-2011; Reagan, Matthew/D-1129-2015 OI Ghanem, Roger/0000-0002-1890-920X; Le Maitre, Olivier/0000-0002-3811-7787; Reagan, Matthew/0000-0001-6225-4928 NR 26 TC 20 Z9 20 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 375 EP 394 DI 10.1137/S1064827503422853 PG 20 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100003 ER PT J AU Higdon, D Kennedy, M Cavendish, JC Cafeo, JA Ryne, RD AF Higdon, D Kennedy, M Cavendish, JC Cafeo, JA Ryne, RD TI Combining field data and computer simulations for calibration and prediction SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE calibration; computer experiments; predictability; uncertainty quantification; Gaussian process; model validation; simulator science ID COMPOSITE NULL MODELS; BAYESIAN PREDICTION; BEAM DYNAMICS; P-VALUES; UNCERTAINTY; INFERENCE; SYSTEMS; DESIGN; CODE AB We develop a statistical approach for characterizing uncertainty in predictions that are made with the aid of a computer simulation model. Typically, the computer simulation code models a physical system and requires a set of inputs - some known and specified, others unknown. A limited amount of field data from the true physical system is available to inform us about the unknown inputs and also to inform us about the uncertainty that is associated with a simulation-based prediction. The approach given here allows for the following: uncertainty regarding model inputs (i.e., calibration); accounting for uncertainty due to limitations on the number of simulations that can be carried out; discrepancy between the simulation code and the actual physical system; uncertainty in the observation process that yields the actual field data on the true physical system. The resulting analysis yields predictions and their associated uncertainties while accounting for multiple sources of uncertainty. We use a Bayesian formulation and rely on Gaussian process models to model unknown functions of the model inputs. The estimation is carried out using a Markov chain Monte Carlo method. This methodology is applied to two examples: a charged particle accelerator and a spot welding process. C1 Los Alamos Natl Lab, Stat Sci Grp, Los Alamos, NM 87545 USA. Univ Sheffield, Dept Probabil & Stat, Sheffield, S Yorkshire, England. Gen Motors R&D Ctr, Mfg Syst Res Lab, Warren, MI 48090 USA. Gen Motors R&D Ctr, Vehicle Dev Res Lab, Warren, MI 48090 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Higdon, D (reprint author), Los Alamos Natl Lab, Stat Sci Grp, MS F600, Los Alamos, NM 87545 USA. EM dhigdon@lanl.gov; m.kennedy@sheffield.ac.uk; james.c.cavendish@gm.com; john.cafeo@gm.com; rdryne@lbl.gov NR 33 TC 198 Z9 200 U1 4 U2 26 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 448 EP 466 DI 10.1137/S1064827503426693 PG 19 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100006 ER PT J AU Lu, ZM Zhang, DX AF Lu, ZM Zhang, DX TI Comparative study on uncertainty quantification for flow in randomly heterogeneous media using Monte Carlo simulations and conventional and KL-based moment-equation approaches SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE Monte Carlo simulations; moment-equation approach; Karhunen-Loeve decomposition; heterogeneity; flow and transport; porous media ID HIGHER-ORDER CORRECTIONS; RANDOM POROUS-MEDIA; STEADY-STATE FLOW; STOCHASTIC-ANALYSIS; LOCALIZED ANALYSES; GROUNDWATER-FLOW; UNSATURATED FLOW; TRANSPORT; NONSTATIONARY; MACRODISPERSION AB Geological formations are ubiquitously heterogeneous, and the equations that govern flow and transport in such formations can be treated as stochastic partial differential equations. The Monte Carlo method is a straightforward approach for simulating flow in heterogeneous porous media; an alternative based on the moment-equation approach has been developed in the last two decades to reduce the high computational expense required by the Monte Carlo method. However, the computational cost of the moment-equation approach is still high. For example, to solve head covariance up to first order in terms of sigma(Y)(2), the variance of log hydraulic conductivity Y = ln K-s, it is required to solve sets of linear algebraic equations with N unknowns for 2N times ( N being the number of grid nodes). The cost is even higher if higher-order approximations are needed. Zhang and Lu [J. Comput. Phys., 194 (2004), pp. 773-794] developed a new approach to evaluate high-order moments (fourth order for mean head in terms of sigma(Y), and third order for head variances in terms of sigma(Y)(2)) of flow quantities based on the combination of Karhunen-Loeve decomposition and perturbation methods. In this study, we systematically investigate the computational efficiency and solution accuracy of three approaches: Monte Carlo simulations, the conventional moment-equation (CME) approach, and the moment-equation approach based on Karhunen-Loeve decomposition (KLME). It is evident that the computational cost for the KLME approach is significantly lower than those required by the Monte Carlo and CME approaches. More importantly, while the computational costs ( in terms of the number of times for solving linear algebraic equations with N unknowns) for the CME approach depend on the number of grid nodes, the cost for the KLME approach is independent of the number of grid nodes. This makes it possible to apply the KLME method to solve more realistic large-scale flow problems. C1 Los Alamos Natl Lab, Hydrol Geochem & Geol Grp EES 6, Los Alamos, NM 87545 USA. RP Lu, ZM (reprint author), Los Alamos Natl Lab, Hydrol Geochem & Geol Grp EES 6, MS T003, Los Alamos, NM 87545 USA. EM zhiming@lanl.gov; donzhang@lanl.gov RI Zhang, Dongxiao/D-5289-2009; OI Zhang, Dongxiao/0000-0001-6930-5994; Lu, Zhiming/0000-0001-5800-3368 NR 40 TC 27 Z9 28 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 558 EP 577 DI 10.1137/S1064827503426826 PG 20 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100012 ER PT J AU Tartakovsky, DM Guadagnini, A AF Tartakovsky, DM Guadagnini, A TI Effective properties of random composites SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE composite media; random fields; stochastic; moment equations; apparent; equivalent ID POROUS-MEDIA; MEAN FLOW AB We propose a new concept of the effective properties of composites with uncertain spatial arrangements of constitutive materials and within-material properties. Rather than replacing a heterogeneous property with a constant effective parameter, we seek to preserve the internal macro structure of a composite. This general concept is used to derive the effective conductivity of composite heterogeneous media that consist of two materials whose internal geometries and conductivities are uncertain. Our analysis relies on a random domain decomposition to explicitly account for the separate effects of material and geometric uncertainties on the ensemble moments of pressure and flux. We present a general expression for the effective (apparent) conductivity of such media and analyze it in detail for one- and two-dimensional steady flows in bounded random media composed of two materials with highly contrasting conductivities. C1 Los Alamos Natl Lab, Div Theoret, Math Modeling & Anal Grp T 7, Los Alamos, NM 87545 USA. Politecn Milan, Dipartimento Ingn Idraulica Ambientale Infrastrut, I-20133 Milan, Italy. RP Tartakovsky, DM (reprint author), Los Alamos Natl Lab, Div Theoret, Math Modeling & Anal Grp T 7, MS B284, Los Alamos, NM 87545 USA. EM dmt@lanl.gov; alberto.guadagnini@polimi.it RI Tartakovsky, Daniel/E-7694-2013 NR 7 TC 3 Z9 3 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 625 EP 635 DI 10.1137/S106482750342711X PG 11 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100016 ER PT J AU Barhen, J Protopopescu, V Reister, DB AF Barhen, J Protopopescu, V Reister, DB TI Consistent uncertainty reduction in modeling nonlinear systems SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE nonlinear systems; sensitivity analysis; uncertainty reduction; automated differentiation ID NON-LINEAR SYSTEMS; SENSITIVITY THEORY; AUTOMATIC DIFFERENTIATION; THERMAL-HYDRAULICS; EQUATIONS AB We present a fairly general time-independent framework for performing systematic and reliable uncertainty analysis of computer-implemented models of complex nonlinear systems. Within this framework, we provide the first formal proof of uncertainty reduction in system parameters and responses, which is achieved by consistently combining model-predicted responses and their associated uncertainties with experimental (e.g., sensor-based) information. MODTRAN - a very large, complex code that models optical radiation transport in the atmosphere - provides an excellent example to illustrate the approach. The sensitivities needed to propagate uncertainties from inputs and parameters to outputs through the complex chain of modules are calculated by automated differentiation. C1 Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. RP Barhen, J (reprint author), Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. EM barahenj@ornl.gov; vvp@ornl.gov; dbr@ornl.gov NR 41 TC 2 Z9 2 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 653 EP 665 DI 10.1137/S1064827503427522 PG 13 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100018 ER PT J AU Glimm, J Grove, JW Kang, YH Lee, T Li, XL Sharp, DH Yu, Y Ye, K Zhao, M AF Glimm, J Grove, JW Kang, YH Lee, T Li, XL Sharp, DH Yu, Y Ye, K Zhao, M TI Statistical Riemann problems and a composition law for errors in numerical solutions of shock physics problems SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE uncertainty quantification; error model; composition law; Riemann problem ID PREDICTION; QUANTIFICATION; UNCERTAINTY AB We seek error models for shock physics simulations that are robust and understandable. The purpose of this paper is to formulate and validate a composition law to estimate errors in the solutions of composite problems in terms of the errors from simpler ones. We illustrate this idea in a simple context. This paper employs several simplifying assumptions (restriction to one spatial dimension, use of a simplified (gamma law) equation of state, and consideration of a single numerical method). In separate papers we will address the effect of these assumptions. C1 SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Ctr Data Intens Comp, Upton, NY USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Glimm, J (reprint author), SUNY Stony Brook, Dept Appl Math & Stat, Stony Brook, NY 11794 USA. EM glimm@ams.sunysb.edu; jgrove@lanl.gov; ykang@lanl.gov; twlee@ams.sunysb.edu; linli@ams.sunysb.edu; dhs@t13.lanl.gov; yan2000@ams.sunysb.edu; kye@ams.sunysb.edu; mingzhao@ams.sunysb.edu NR 21 TC 6 Z9 7 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 666 EP 697 DI 10.1137/S1064827503427534 PG 32 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100019 ER PT J AU Debusschere, BJ Najm, HN Pebay, PP Knio, OM Ghanem, RG Le Maitre, OP AF Debusschere, BJ Najm, HN Pebay, PP Knio, OM Ghanem, RG Le Maitre, OP TI Numerical challenges in the use of polynomial chaos representations for stochastic processes SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE polynomial chaos; stochastic; spectral uncertainty quantification ID PROJECTION METHOD; FINITE-ELEMENTS; FLUID-FLOW; UNCERTAINTY; WIENER AB This paper gives an overview of the use of polynomial chaos (PC) expansions to represent stochastic processes in numerical simulations. Several methods are presented for performing arithmetic on, as well as for evaluating polynomial and nonpolynomial functions of variables represented by PC expansions. These methods include Taylor series, a newly developed integration method, as well as a sampling-based spectral projection method for nonpolynomial function evaluations. A detailed analysis of the accuracy of the PC representations, and of the different methods for nonpolynomial function evaluations, is performed. It is found that the integration method offers a robust and accurate approach for evaluating nonpolynomial functions, even when very high-order information is present in the PC expansions. C1 Sandia Natl Labs, Livermore, CA 94550 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Evry Val Essonne, Evry, France. RP Debusschere, BJ (reprint author), Sandia Natl Labs, 7011 E Ave,MS 9051, Livermore, CA 94550 USA. EM bjdebus@sandia.gov; hnnajm@sandia.gov; pppebay@ca.sandia.gov; knio@jhu.edu; ghanem@jhu.edu; olm@iup.univ-evry.fr RI Knio, Omar/A-3318-2010; Ghanem, Roger/B-8570-2008; Le Maitre, Olivier/D-8570-2011; OI Ghanem, Roger/0000-0002-1890-920X; Le Maitre, Olivier/0000-0002-3811-7787; Pebay, Philippe/0000-0002-2311-3775 NR 31 TC 162 Z9 164 U1 0 U2 23 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 26 IS 2 BP 698 EP 719 DI 10.1137/S1064827503427741 PG 22 WC Mathematics, Applied SC Mathematics GA 894WU UT WOS:000226823100020 ER PT J AU Gray, LJ Glaeser, JM Kaplan, T AF Gray, LJ Glaeser, JM Kaplan, T TI Direct evaluation of hypersingular Galerkin surface integrals SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE boundary integral method; hypersingular integrals; Galerkin approximation; Laplace equation ID BOUNDARY-ELEMENT METHOD; CRACK PROBLEMS; 3-DIMENSIONAL ELASTICITY; LINEAR ELASTICITY; FRACTURE-ANALYSIS; 3D BEM; EQUATIONS; KERNEL; STRESS AB A direct algorithm for evaluating hypersingular integrals arising in a three-dimensional Galerkin boundary integral analysis is presented. The singular integrals are defined as limits to the boundary, and by integrating two of the four dimensions analytically, the coincident integral is shown to be divergent. However, the divergent terms can be explicitly calculated and shown to cancel with corresponding singularities in the adjacent edge integrals. A single analytic integration is employed for the edge and vertex singular integrals. This is sufficient to display the divergent term in the edge-adjacent integral and to show that the vertex integral is finite. By explicitly identifying the divergent quantities, we can compute the hypersingular integral without recourse to Stokes's theorem or the Hadamard finite part. The algorithms are developed in the context of a linear element approximation for the Laplace equation but are expected to be generally applicable. As an example, the algorithms are applied to solve a thermal problem in an exponentially graded material. C1 Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Lockheed Martin Naval Elect & Surveillance Syst, Moorestown, NJ 08057 USA. RP Gray, LJ (reprint author), Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. EM ljg@ornl.gov; julia.glaeser@lmco.com; tsk@ornl.gov NR 61 TC 39 Z9 39 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 25 IS 5 BP 1534 EP 1556 DI 10.1137/S1064827502405999 PG 23 WC Mathematics, Applied SC Mathematics GA 827UC UT WOS:000221925600004 ER PT J AU Barth, T Bochev, P Gunzburger, M Shadid, J AF Barth, T Bochev, P Gunzburger, M Shadid, J TI A taxonomy of consistently stabilized finite element methods for the Stokes problem SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE stabilized finite element methods; mixed methods; iterative solvers; coercive forms ID COMPUTATIONAL FLUID-DYNAMICS; LINEAR-SYSTEMS; FORMULATION AB Stabilized mixed methods can circumvent the restrictive inf-sup condition without introducing penalty errors. For properly chosen stabilization parameters these methods are well-posed for all conforming velocity-pressure pairs. However, their variational forms have widely varying properties. First, stabilization offers a choice between weakly or strongly coercive bilinear forms that give rise to linear systems with identical solutions but very different matrix properties. Second, coercivity may be conditional upon a proper choice of a stabilizing parameter. Here we focus on how these two aspects of stabilized methods affect their accuracy and efficient iterative solution. We present results that indicate a preference of Krylov subspace solvers for strongly coercive formulations. Stability criteria obtained by finite element and algebraic analyses are compared with numerical experiments. While for two popular classes of stabilized methods, sufficient stability bounds correlate well with numerical stability, our experiments indicate the intriguing possibility that the pressure-stabilized Galerkin method is unconditionally stable. C1 Sandia Natl Labs, Computat Math & Algorithms Dept, Albuquerque, NM 87185 USA. Florida State Univ, Sch Computat Sci & Informat Technol, Tallahassee, FL 32306 USA. Sandia Natl Labs, Dept Computat Sci, Albuquerque, NM 87185 USA. RP Barth, T (reprint author), Sandia Natl Labs, Computat Math & Algorithms Dept, POB 5800, Albuquerque, NM 87185 USA. EM tlbarth@sandia.gov; pbboche@sandia.gov; gunzburg@csit.fsu.edu; jnshadi@sandia.gov NR 24 TC 53 Z9 55 U1 0 U2 3 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 25 IS 5 BP 1585 EP 1607 DI 10.1137/S1064827502407718 PG 23 WC Mathematics, Applied SC Mathematics GA 827UC UT WOS:000221925600006 ER PT J AU Aykanat, C Pinar, A Catalyurek, UV AF Aykanat, C Pinar, A Catalyurek, UV TI Permuting sparse rectangular matrices into block-diagonal form SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE coarse-grain parallelism; sparse rectangular matrices; singly bordered block-diagonal form; doubly bordered block-diagonal form; graph partitioning by vertex separator; hypergraph partitioning ID ANGULAR LINEAR-PROGRAMS; NESTED DISSECTION; DECOMPOSITION; OPTIMIZATION AB We investigate the problem of permuting a sparse rectangular matrix into block-diagonal form. Block-diagonal form of a matrix grants an inherent parallelism for solving the deriving problem, as recently investigated in the context of mathematical programming, LU factorization, and QR factorization. To represent the nonzero structure of a matrix, we propose bipartite graph and hypergraph models that reduce the permutation problem to those of graph partitioning by vertex separator and hypergraph partitioning, respectively. Our experiments on a wide range of matrices, using the state-of-the-art graph and hypergraph partitioning tools MeTiS and PaToH, revealed that the proposed methods yield very effective solutions both in terms of solution quality and runtime. C1 Bilkent Univ, Dept Comp Engn, Ankara, Turkey. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ohio State Univ, Dept Biomed Informat, Columbus, OH 43210 USA. RP Bilkent Univ, Dept Comp Engn, Ankara, Turkey. EM aykanat@cs.bilkent.edu.tr; apinar@lbl.gov; catalyurek.1@osu.edu RI Catalyurek, Umit/A-2454-2008 OI Catalyurek, Umit/0000-0002-5625-3758 NR 43 TC 56 Z9 56 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 EI 1095-7197 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 25 IS 6 BP 1860 EP 1879 DI 10.1137/S1064827502401953 PG 20 WC Mathematics, Applied SC Mathematics GA 857LR UT WOS:000224118700002 ER PT J AU Hirshman, SP Berry, LA Jesse, S AF Hirshman, SP Berry, LA Jesse, S TI Dynamic database generation for efficient calculation of stellarator plasma equilibria SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE dynamic database; optimization; linked list; stellarator; plasma equilibrium AB A numerical scheme has been developed and tested that significantly reduces ( by a factor of 30, typically) both the computation time and storage requirements for external magnetic field calculations embedded in a three-dimensional iterative magnetohydrodynamic equilibrium calculation. The equilibrium is computed from external magnetic fields that are calculated numerically using the Biot - Savart law applied to a complex set of coils. These fields must be evaluated on the plasma boundary, which evolves as the equilibrium converges. The improved efficiency of the present method results from dynamically building and storing a database of magnetic field components on a grid that is determined by the changing plasma boundary itself. When possible, field values on the plasma boundary for a particular iteration are interpolated from these grid values, thus eliminating the need for further time-consuming Biot - Savart calculations. New grid points are added to the database only when the boundary moves outside the spatial range of previously computed interpolation values. This dynamical method is particularly efficient when the equilibrium calculation is embedded in an optimization loop, where evolution of the coil set requires many reevaluations of the database. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM hirshmansp@ornl.gov; berryla@ornl.gov; sjesse@utk.edu RI Jesse, Stephen/D-3975-2016 OI Jesse, Stephen/0000-0002-1168-8483 NR 9 TC 0 Z9 0 U1 0 U2 1 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 EI 1095-7197 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 25 IS 6 BP 1880 EP 1895 DI 10.1137/S106482750342458X PG 16 WC Mathematics, Applied SC Mathematics GA 857LR UT WOS:000224118700003 ER PT J AU Brezina, M Falgout, R MacLachlan, S Manteuffel, T McCormick, S Ruge, J AF Brezina, M Falgout, R MacLachlan, S Manteuffel, T McCormick, S Ruge, J TI Adaptive smoothed aggregation (alpha SA) SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE algebraic multigrid (AMG); generalized smoothed aggregation (SA); adaptive method ID CONVERGENCE; SOLVER AB Substantial effort has been focused over the last two decades on developing multilevel iterative methods capable of solving the large linear systems encountered in engineering practice. These systems often arise from discretizing partial differential equations over unstructured meshes, and the particular parameters or geometry of the physical problem being discretized may be unavailable to the solver. Algebraic multigrid (AMG) and multilevel domain decomposition methods of algebraic type have been of particular interest in this context because of their promises of optimal performance without the need for explicit knowledge of the problem geometry. These methods construct a hierarchy of coarse problems based on the linear system itself and on certain assumptions about the smooth components of the error. For smoothed aggregation ( SA) methods applied to discretizations of elliptic problems, these assumptions typically consist of knowledge of the near-nullspace of the weak form. This paper introduces an extension of the SA method in which good convergence properties are achieved in situations where explicit knowledge of the near-nullspace components is unavailable. This extension is accomplished by using the method itself to determine near-nullspace components and adjusting the coarsening processes accordingly. C1 Univ Colorado, Dept Appl Math, Boulder, CO 80309 USA. Lawrence Livermore Natl Lab, Ctr Appl Sci Computat, Livermore, CA 94551 USA. RP Brezina, M (reprint author), Univ Colorado, Dept Appl Math, Campus Box 526, Boulder, CO 80309 USA. EM mbrezina@math.cudenver.edu; rfalgout@llnl.gov; scott.maclachlan@colorado.edu; tmanteuf@boulder.colorado.edu; stevem@boulder.colorado.edu; jruge@boulder.colorado.edu NR 23 TC 51 Z9 51 U1 0 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 25 IS 6 BP 1896 EP 1920 DI 10.1137/S1064827502418598 PG 25 WC Mathematics, Applied SC Mathematics GA 857LR UT WOS:000224118700004 ER PT J AU Bennighof, JK Lehoucq, RB AF Bennighof, JK Lehoucq, RB TI An automated multilevel substructuring method for eigenspace computation in linear elastodynamics SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE eigenvalues; modal analysis; multilevel; substructuring; domain decomposition; dimensional reduction; finite elements; frequency response ID COMPONENT MODE SYNTHESIS AB We present an automated multilevel substructuring (AMLS) method for eigenvalue computations in linear elastodynamics in a variational and algebraic setting. AMLS first recursively partitions the domain of the PDE into a hierarchy of subdomains. Then AMLS recursively generates a subspace for approximating the eigenvectors associated with the smallest eigenvalues by computing partial eigensolutions associated with the subdomains and the interfaces between them. We remark that although we present AMLS for linear elastodynamics, our formulation is abstract and applies to generic H-1-elliptic bilinear forms. In the variational formulation, we define an interface mass operator that is consistent with the treatment of elastic properties by the familiar Steklov-Poincare operator. With this interface mass operator, all of the subdomain and interface eigenvalue problems in AMLS become orthogonal projections of the global eigenvalue problem onto a hierarchy of subspaces. Convergence of AMLS is determined in the continuous setting by the truncation of these eigenspaces, independent of other discretization schemes. The goal of AMLS, in the algebraic setting, is to achieve a high level of dimensional reduction, locally and inexpensively, while balancing the errors associated with truncation and the finite element discretization. This is accomplished by matching the mesh-independent AMLS truncation error with the finite element discretization error. Our report ends with numerical experiments that demonstrate the effectiveness of AMLS on a model problem and an industrial problem. C1 Univ Texas, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bennighof, JK (reprint author), Univ Texas, Dept Aerosp Engn & Engn Mech, Austin, TX 78712 USA. EM bennighof@mail.utexas.edu; rblehou@sandia.gov NR 15 TC 71 Z9 71 U1 0 U2 7 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PY 2004 VL 25 IS 6 BP 2084 EP 2106 DI 10.1137/S1064827502400650 PG 23 WC Mathematics, Applied SC Mathematics GA 857LR UT WOS:000224118700013 ER PT B AU Pan, GR Yim, H Kent, MS Majewski, J Schaefer, DW AF Pan, GR Yim, H Kent, MS Majewski, J Schaefer, DW BE Mittal, KL TI Effect of bridging group on the structure of bis-silane water-barrier films SO SILANES AND OTHER COUPLING AGENTS, VOL 3 LA English DT Proceedings Paper CT 4th International Symposium on Silanes and Other Coupling Agents CY JUN 11-13, 2003 CL Orlando, FL DE silane; neutron reflectivity; degradation; swelling; bridging group ID ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY; ALLOY-COATED STEEL; NEUTRON REFLECTION; SILICON-WAFERS; TOF-SIMS; ADSORPTION; ALUMINUM; LAYERS; AL; FINISH AB Silane molecular structure, including functionality and the length and character of organic modifying group, is the key factor that controls the performance of silane films in corrosion protection applications. In this paper, we review the use of neutron reflectivity to determine the influence of the bridging group on the swelling of bis-silane films. Our goal is to clarify the relationship between silane molecular structure, silane film morphology and water barrier performance while developing a database for optimizing the performance in anti-corrosion applications. In nitrobenzene, bis-trimethoxysilylpropylamine (bis-amino silane) swells more than bis-triethoxysilylethane (BTSE), a behavior that we attribute to differences in crosslink density. From swelling studies using deuterated nitrobenzene, we conclude that the crosslink density of BTSE is higher than that of bis-amino silane. High crosslink density leads to improved water-barrier performance and explains why bis-silanes are more effective than monosilanes as water barrier films. Bis-amino silane is found to swell more in water than in nitrobenzene, which indicates the importance of the character of the bridging group. The secondary amino group is the driving force for absorbing water. Finally, we observe exchange of the amine proton by the deuteron when bis-amino silane is swollen in heavy water. C1 Univ Cincinnati, Dept Chem & Mat Engn, Cincinnati, OH 45221 USA. Univ Cincinnati, Polymer Res Ctr, Cincinnati, OH 45221 USA. Sandia Natl Labs, Dept 1811, Albuquerque, NM 87185 USA. Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87585 USA. RP Pan, GR (reprint author), Univ Cincinnati, Dept Chem & Mat Engn, Cincinnati, OH 45221 USA. RI Lujan Center, LANL/G-4896-2012 NR 21 TC 0 Z9 0 U1 1 U2 4 PU VSP BV-C/O BRILL ACAD PUBL PI LEIDEN PA PO BOX 9000, 2300 PA LEIDEN, NETHERLANDS BN 90-6764-404-8 PY 2004 BP 39 EP 49 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA BCF58 UT WOS:000229040600004 ER PT S AU Gao, F Weber, WJ Posselt, M Belko, V AF Gao, F Weber, WJ Posselt, M Belko, V BE Madar, R Camassel, J TI Atomic computer simulations of defect migration in 3C and 4H-SiC SO SILICON CARBIDE AND RELATED MATERIALS 2003, PRTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 10th International Conferece on Silicon Carbide and Related Materials 2003 (ICSCRM 2003) CY OCT 05-10, 2003 CL Lyon, FRANCE DE defect diffusion; activation energy; molecular dynamics; nudged-elastic band method ID RECOVERY; ACCUMULATION AB Knowledge of the migration of intrinsic point defects is crucial to understand defect recovery, various annealing stages and microstructural evolution after irradiation or ion implantation. Molecular dynamics (MD) and the nudged-elastic band method have been applied to investigate long-range migration of point defects in SiC over the temperature range from 0.36 to 0.95 T-m, and the defect diffusion coefficient, activation energy and defect correlation factor have been determined. The results show that the activation energies for C and Si interstitials in 3C-SiC are about 0.74 and 1.53 eV, respectively, while it is about 0.77 eV for a C interstitial in 4H-SiC. The minima energy paths reveal that the activation energies for C and Si vacancies are about 4.1 and 2.35 eV, respectively. Finally, the results are discussed and compared with experimental observations and available ab initio data. C1 Pacific NW Natl Lab, Fundamental Sci Directorate, Richland, WA 99352 USA. Forschungszentrum Rossendorf EV, Inst Ion Beam Phys & Mat Res, D-01314 Dresden, Germany. Belarussian State Univ, Dept Math Phys, Minsk 220050, Byelarus. RP Gao, F (reprint author), Pacific NW Natl Lab, Fundamental Sci Directorate, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; Gao, Fei/H-3045-2012 OI Weber, William/0000-0002-9017-7365; NR 13 TC 4 Z9 4 U1 0 U2 6 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2004 VL 457-460 BP 457 EP 460 PN 1&2 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA BAM18 UT WOS:000222802200106 ER PT S AU Usov, IO Suvorova, AA Suvorov, A AF Usov, IO Suvorova, AA Suvorov, A BE Madar, R Camassel, J TI Effect of implantation temperature on redistribution of Al in SiC during annealing SO SILICON CARBIDE AND RELATED MATERIALS 2003, PRTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 10th International Conferece on Silicon Carbide and Related Materials 2003 (ICSCRM 2003) CY OCT 05-10, 2003 CL Lyon, FRANCE DE ion implantation; radiation damage; diffusion ID TRANSIENT ENHANCED DIFFUSION; ION-IMPLANTATION; SILICON-CARBIDE; ALUMINUM; BORON AB Diffusion of aluminum in 6H-SiC during high temperature annealing was studied. Al atoms were introduced by ion implantation at various substrate temperatures. It has been shown that redistribution of Al atoms during the following annealing correlated with the amount and nature of residual damage created by ion bombardment. C1 Los Alamos Natl Lab, MST, STC, Los Alamos, NM 87544 USA. Univ Western Australia, Ctr Microscopy & Microanal, Crawley, WA 6009, Australia. Cree Inc, Durham, NC 27703 USA. RP Usov, IO (reprint author), Los Alamos Natl Lab, MST, STC, POB 1663, Los Alamos, NM 87544 USA. RI Suvorova, Alexandra/B-9335-2011 OI Suvorova, Alexandra/0000-0001-8970-6058 NR 11 TC 1 Z9 1 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2004 VL 457-460 BP 897 EP 900 PN 1&2 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA BAM18 UT WOS:000222802200213 ER PT S AU Declemy, A Shiryaev, A Stepanov, S Barbot, JF Beaufort, MF Oliviero, E Ntsoenzok, E Sauvage, T AF Declemy, A Shiryaev, A Stepanov, S Barbot, JF Beaufort, MF Oliviero, E Ntsoenzok, E Sauvage, T BE Madar, R Camassel, J TI Contribution of X-Ray Diffraction simulations to experimental study of high energy He implantation at high dose in 4H-SiC at room temperature SO SILICON CARBIDE AND RELATED MATERIALS 2003, PRTS 1 AND 2 SE MATERIALS SCIENCE FORUM LA English DT Article; Proceedings Paper CT 10th International Conferece on Silicon Carbide and Related Materials 2003 (ICSCRM 2003) CY OCT 05-10, 2003 CL Lyon, FRANCE DE silicon carbide; ion implantation; X-ray Diffraction; dynamical diffraction theory ID ION; IRRADIATION; SCATTERING; DAMAGE AB Damage induced by 1.6 MeV helium implantation of 2x10(+16) ions/cm(2) in 4H-SiC, at room temperature, was characterized using X-ray Diffraction (XRD) experiments and simulations. C1 LMP, SP2MI, F-86960 Futuroscope, France. AV Shubnikov Crystallog Inst, Moscow, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. CNRS, CERI, F-45071 Orleans, France. RP Declemy, A (reprint author), LMP, SP2MI, BP 30179, F-86960 Futuroscope, France. RI Shiryaev, Andrei/F-7643-2012; OI Oliviero, Erwan/0000-0002-7828-9137 NR 15 TC 1 Z9 1 U1 0 U2 1 PU TRANS TECH PUBLICATIONS LTD PI ZURICH-UETIKON PA BRANDRAIN 6, CH-8707 ZURICH-UETIKON, SWITZERLAND SN 0255-5476 J9 MATER SCI FORUM PY 2004 VL 457-460 BP 937 EP 940 PN 1&2 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA BAM18 UT WOS:000222802200223 ER PT S AU Carroll, MS Sturm, JC AF Carroll, MS Sturm, JC BE Pichler, P Claverie, A Lindsay, R Orlowski, M Windl, W TI Boron diffusion and silicon self-interstitial recycling between SiGeC layers SO SILICON FRONT-END JUNCTION FORMATION-PHYSICS AND TECHNOLOGY SE Materials Research Society Symposium Proceedings LA English DT Proceedings Paper CT Symposium on Silicon Front-End Junction Formation-Physics and Technology held at the 2004 MRS Spring Meeting CY APR 13-15, 2004 CL San Francisco, CA SP Mat Res Soc ID OXIDATION-ENHANCED DIFFUSION; POINT-DEFECTS; COMMON DOPANTS; SI AB Substitutional carbon is known to locally reduce silicon self-interstitial concentrations and act as a barrier to self-interstitial migration through the carbon rich regions. A silicon spacer between two carbon rich SiGe layers is fabricated it, this work to examine self-interstitial generation in a region that is isolated from self-interstitial formation at the surface or in the silicon bulk. Boron marker layers above, below and in between two SiGeC layers are used to monitor the self-interstitial concentration between the substitutional carbon. No evidence of self-interstitial depletion in the silicon spacer is observed, despite annealing in conditions believed sufficient to allow the self-interstitials to reach and react with surrounding substitutional carbon. Simulations of the self-interstitial and carbon indicate that the silicon self interstitial concentration in the spacer layer can be sustained in part due to a silicon self-interstitial recycling process through a reverse "kick-out" reaction. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Carroll, MS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 0 Z9 0 U1 1 U2 1 PU MATERIALS RESEARCH SOC PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-760-1 J9 MATER RES SOC SYMP P PY 2004 VL 810 BP 85 EP 90 PG 6 WC Engineering, Electrical & Electronic; Materials Science, Ceramics; Physics, Condensed Matter SC Engineering; Materials Science; Physics GA BBA54 UT WOS:000224411300011 ER PT J AU Wyss, GD Duran, FA Dandini, VJ AF Wyss, GD Duran, FA Dandini, VJ TI An object-oriented approach to risk and reliability analysis: Methodology and aviation safety applications SO SIMULATION-TRANSACTIONS OF THE SOCIETY FOR MODELING AND SIMULATION INTERNATIONAL LA English DT Article DE object-oriented methods; probabilistic methods; event tree analysis; probabilistic risk assessment (PRA) AB This article describes how features of event tree analysis and Monte Carlo-based discrete event simulation can be combined with concepts from object-oriented analysis to develop a new risk assessment methodology, with some of the best features of each. The resultant object-based event scenario tree (OBEST) methodology enables an analyst to rapidly construct realistic models for scenarios for which an a priori discovery of event ordering is either cumbersome or impossible. Each scenario produced by OBEST is automatically associated with a likelihood estimate because probabilistic branching is integral to the object model definition. The OBEST methodology is then applied to an aviation safety problem that considers mechanisms by which an aircraft might become involved in a runway incursion incident. The resulting OBEST model demonstrates how a close link between human reliability analysis and probabilistic risk assessment methods can provide important insights into aviation safety phenomenology. C1 Sandia Natl Labs, Vulnerabil & Risk Anal Dept, Albuquerque, NM 87185 USA. RP Wyss, GD (reprint author), Sandia Natl Labs, Vulnerabil & Risk Anal Dept, POB 5800,MS 0748, Albuquerque, NM 87185 USA. EM gdwyss@sandia.gov NR 12 TC 4 Z9 5 U1 1 U2 2 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 0037-5497 J9 SIMUL-T SOC MOD SIM JI Simul.-Trans. Soc. Model. Simul. Int. PD JAN PY 2004 VL 80 IS 1 BP 33 EP 43 DI 10.1177/0037549704042033 PG 11 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA 802JA UT WOS:000220158600004 ER PT S AU Kadau, K Germann, TC Hadjiconstantinou, NG Dimonte, G Lomdahl, PS Holian, BL Alder, BJ AF Kadau, K Germann, TC Hadjiconstantinou, NG Dimonte, G Lomdahl, PS Holian, BL Alder, BJ BE Tokuyama, M Oppenheim, I TI Molecular dynamics compared to hydrodynamics for Rayleigh-Taylor instability SO SLOW DYNAMICS IN COMPLEX SYSTEMS SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 3rd International Symposium on Slow Dynamics in Complex Systems CY NOV 03-08, 2003 CL Sendai, JAPAN SP Tohoku Univ, Inst Fluid Sci, Minist Educ, Culture, Sports, Sci & Technol Japan AB A massively parallel molecular-dynamics (MD) simulation of some 100 million particles is compared to theoretical Navier-Stokes (NS) predictions, continuum NS simulations, and experimental observations of the Rayleigh-Taylor fluid instability. Smaller MD simulations were performed to verify the initial exponential rise of a single bubble, as predicted analytically for both miscible and immiscible fluids. The penetration of spikes of heavy fluid into light, along with bubbles of light rising into heavy, grows as the square of time at long times-with experiment and both atomistic and continuum computer simulation in 20% agreement. However, part of the differences may be due to dependence upon initial conditions, whose influence on the growth of individual modes was studied for two different cases: an initial interface formed by a single sinusoidal perturbation vs. one perturbed only by thermal fluctuations. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kadau, K (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0183-7 J9 AIP CONF PROC PY 2004 VL 708 BP 376 EP 378 PG 3 WC Materials Science, Ceramics; Physics, Fluids & Plasmas; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA BAI16 UT WOS:000222360700128 ER PT S AU McKnight, TE Melechko, AV Griffin, GD Austin, DW Sims, T Guillorn, MA Merkulov, V Simpson, ML AF McKnight, TE Melechko, AV Griffin, GD Austin, DW Sims, T Guillorn, MA Merkulov, V Simpson, ML BE Cullum, BM TI Carbon nanofiber-based probing arrays for multipoint integration with cellular matrices SO SMART MEDICAL AND BIOMEDICAL SENSOR TECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Medical and Biomedical Sensor Technology CY OCT 28-29, 2003 CL Providence, RI SP SPIE DE carbon nanofibers; electrochemistry; cell probing; microfabrication; DNA delivery ID NANOTUBES; GROWTH; PROBES; ELECTROCHEMISTRY; NANOSTRUCTURES; CELLS AB The self-assembling and controlled synthesis properties of vertically-aligned carbon nanofibers (VACNF) have been exploited to provide parallel subcellular and molecular-scale probes for biological manipulation and monitoring. VACNFs possess many attributes that make them very attractive for implementation as functional, nanoscale features of microfabricated devices. For example, they can be synthesized at precise locations upon a substrate, can be grown many microns long, and feature sharp, nano-dimensioned tips. They also exhibit characteristic electrochemical responses similar to conventionally studied materials such as the edge plane of pyrolytic graphite and surface-activated glassy carbon. This, and their needlelike, vertical orientation upon a substrate, makes them particularly attractive as multielement cellular scale probes or as a parallel embodiment of traditional single-point microinjection or microelectrophysiological systems. We will overview our efforts at fabricating and characterizing several embodiments of VACNF cell probing systems. We will also overview surface modification techniques that exploit the rich surface chemistries of VACNF arrays to allow immobilization of active enzymes and transcriptionally active DNA, which can provide sensitivity to specific biological analytes and application of the nanofiber architecture for controlled biochemical manipulation within the cell. Finally, we will overview our techniques of integrating these probing structures with intact cells and how these structures may be used on a massively parallel basis for measurement and control of the intracellular domain. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP McKnight, TE (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Simpson, Michael/A-8410-2011; Melechko, Anatoli/B-8820-2008; McKnight, Tim/H-3087-2011 OI Simpson, Michael/0000-0002-3933-3457; McKnight, Tim/0000-0003-4326-9117 NR 18 TC 0 Z9 0 U1 0 U2 4 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5150-9 J9 P SOC PHOTO-OPT INS PY 2004 VL 5261 BP 155 EP 162 DI 10.1117/12.519972 PG 8 WC Engineering, Biomedical; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BY85U UT WOS:000189479900017 ER PT S AU McKnight, TE Melechko, AV Griffin, GD Jun, SI Rack, P Guillorn, MA Merkulov, V Simpson, ML AF McKnight, TE Melechko, AV Griffin, GD Jun, SI Rack, P Guillorn, MA Merkulov, V Simpson, ML BE Cullum, BM TI Optically and electrically addressed carbon nanofiber electrode arrays for intracellular interfacing SO SMART MEDICAL AND BIOMEDICAL SENSOR TECHNOLOGY II SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Smart Medical and Biomedical Sensor Technology II CY OCT 25-26, 2004 CL Philadelphia, PA SP SPIE, IEICE, Commun Soc, IEICE, Elect Soc DE carbon nanofibers; electrochemistry; cell probing; microfabrication; electrophysiology ID NANOSTRUCTURES; FABRICATION; TEMPLATES AB Progress in the application of vertically-aligned carbon nanofibers (VACNF) as parallel subcellular and molecular-scale probes for biological manipulation and monitoring is reported. VACNFs possess many attributes that make them very attractive for implementation as functional, nanoscale features of microfabricated devices. For example, they can be synthesized at precise locations upon a substrate, can be grown many microns long, and feature sharp, nano-dimensioned tips. This, and their needlelike, vertical orientation upon a substrate, makes them particularly attractive as multielement cellular scale probes or as a parallel embodiment of traditional single-point microinjection or microelectrophysiological systems. We will overview our progress with fabricating and characterizing several embodiments of VACNF cell probing systems, which all feature arrays of nanoscale electrochemically-active probing regions at the tips of individually electrically-addressed nanofiber elements. We also overview our techniques of integrating these probing structures with intact cells and how these structures may be used on a massively parallel basis for measurement and control around and within viable cells. C1 Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RP McKnight, TE (reprint author), Oak Ridge Natl Lab, Condensed Matter Sci Div, Oak Ridge, TN 37831 USA. RI Simpson, Michael/A-8410-2011; Melechko, Anatoli/B-8820-2008; McKnight, Tim/H-3087-2011; OI Simpson, Michael/0000-0002-3933-3457; McKnight, Tim/0000-0003-4326-9117; Rack, Philip/0000-0002-9964-3254 NR 16 TC 0 Z9 0 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5541-5 J9 P SOC PHOTO-OPT INS PY 2004 VL 5588 BP 128 EP 135 DI 10.1117/12.571375 PG 8 WC Biochemical Research Methods; Chemistry, Analytical; Instruments & Instrumentation; Medical Laboratory Technology SC Biochemistry & Molecular Biology; Chemistry; Instruments & Instrumentation; Medical Laboratory Technology GA BBM95 UT WOS:000226252000014 ER PT S AU Datskos, PG Lavrik, NV Sepaniak, MJ AF Datskos, PG Lavrik, NV Sepaniak, MJ BE Yurish, SY Gomes, MTS TI Chemical and biological sensors based on microcantilevers SO SMART SENSORS AND MEMS SE NATO Science Series II-Mathematics Physics and Chemistry LA English DT Proceedings Paper CT Conference of the NATO-Advanced-Study-Institute on Smart Sensors and MEMS CY SEP 08-19, 2003 CL Povoa de Varzim, PORTUGAL SP NATO ASI DE microcantilever; MEMS; micromechanical; resonance; deformation; transducer; stress; chemical sensor; biosensor; analyte; response mechanism; noise; thermo-mechanical; figures of merit ID ATOMIC-FORCE MICROSCOPY; RESONANT GATE TRANSISTOR; ENHANCED CHEMIMECHANICAL TRANSDUCTION; TUNNELING DISPLACEMENT TRANSDUCER; MICROMECHANICAL CANTILEVER ARRAY; SURFACE STRESS MEASUREMENTS; SELF-ASSEMBLED MONOLAYERS; MECHANICAL-THERMAL NOISE; WAVE VAPOR SENSORS; NANOMECHANICAL RESONATORS AB The recent developments in micro-mechanical or micro-electro-mechanical (MEMS) systems have enabled the use of new transduction modes that involve mechanical energy and are based primarily on mechanical phenomena. As a result, an innovative family of chemical and biological sensors has emerged. In this work we discuss the recent advances in cantilever transducers. While MEMS represents a diverse family of designs, devices with simple cantilever configurations. are especially attractive as transducers for chemical and biological sensors. We discuss four important aspects of cantilever transducers, which include operation principles and models, figures of merit, and applications. We also provide a brief analysis of historical predecessors of the modem cantilever sensors. C1 Oak Ridge Natl Lab, Engn Sci & Technol Div, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Engn Sci & Technol Div, Bldg 4500S,Rm H-160,MS 6141,Bethel Valley Rd,MS61, Oak Ridge, TN 37831 USA. EM pgd@ornl.gov RI Lavrik, Nickolay/B-5268-2011 OI Lavrik, Nickolay/0000-0002-9543-5634 NR 200 TC 3 Z9 3 U1 0 U2 5 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1568-2609 BN 1-4020-2927-6 J9 NATO SCI SER II-MATH PY 2004 VL 181 BP 331 EP 379 PG 49 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BCI14 UT WOS:000229429700011 ER PT B AU Datskos, PG Lavrik, NV AF Datskos, PG Lavrik, NV BE Yurish, SY Gomes, MTS TI Uncooled infrared MEMS detectors SO Smart Sensors and MEMS SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT Conference of the NATO-Advanced-Study-Institute on Smart Sensors and MEMS CY SEP 08-19, 2003 CL Povoa de Varzim, PORTUGAL SP NATO ASI DE IR detector; thermal detector; focal place array; MEMS; microcantilever; bolometer; uncooled; figures of merit; responsivity; NETD; response time; noise; temperature fluctuation; thermo-mechanical; thermal isolation ID MECHANICAL-THERMAL NOISE; ATOMIC-FORCE MICROSCOPE; VIBRATION SENSORS; PHOTON DETECTORS; BROWNIAN-MOTION; MICROCANTILEVERS; PERFORMANCE; RESOLUTION; TECHNOLOGY; ARRAYS AB Bimaterial microcantilevers arranged into focal plane arrays (FPAs) can function as uncooled IR imaging devices. In order to analyze the performance of such devices and compare various FPAs, it is essential to have an in-depth understanding of their operation, figures of merit, and fundamental limitations. We give an overview of figures of merit that are applicable to both cooled and uncooled IR detectors. Specific focus of this chapter is a performance analysis for microcantilever IR detectors with an optical readout. We discuss responsivity of microcantilever IR detectors and analyze the different sources (and mechanisms) of noise present in them. A model SiNx microcantilever device with an Al layer in the bimaterial region was fabricated and its performance as an IR detector was analyzed. C1 Oak Ridge Natl Lab, Engn Sci & Technol Div, Oak Ridge, TN 37831 USA. RP Datskos, PG (reprint author), Oak Ridge Natl Lab, Engn Sci & Technol Div, Bldg 4500S,Rm H-160,MS 6141,Bethel Valley Rd,MS61, Oak Ridge, TN 37831 USA. RI Lavrik, Nickolay/B-5268-2011 OI Lavrik, Nickolay/0000-0002-9543-5634 NR 63 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-2927-6 J9 NATO SCI SER II MATH PY 2004 VL 181 BP 381 EP 419 PG 39 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA BCI14 UT WOS:000229429700012 ER PT S AU Xie, J Sansinena, JM Gao, JB Wang, HL AF Xie, J Sansinena, JM Gao, JB Wang, HL BE BarCohen, Y TI Fabrication and characterization of solid-state conducting polymer actuators SO SMART STRUCTURES AND MATERIALS 2004: ELECTROACTIVE POLYMER ACTUATORS AND DEVICES (EAPAD) SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2004 Conference CY MAR 15-18, 2004 CL San Diego, CA SP SPIE, Amer Inst Aeronaut & Astronaut, Amer Soc Mech Engineers, Soc Expt Mech, Boeing Co, Journal Intelligent Mat Syst & Struct, Rhombus Consultants Grp, CSA Engn Inc, ISIS Canada DE polyaniline; solid-state; actuator; force; bending angle ID ARTIFICIAL MUSCLES; POLYANILINE FIBERS; POLYPYRROLE; PERFORMANCE; TRANSPORT; GEL AB We report here the fabrication and characterization of solid-state conducting polymer actuators. The electrochemical activity of polyaniline (PANI) thin film coated with solid-state polyelectrolyte is very similar to the polyaniline thin film in an aqueous solution. The solid-state actuator is adhered to a lever arm of a force transducer and the force generation is measured in real time. The force generated by the actuator is found to be length dependent. However, the overall torque generated by the actuators with different lengths remains essentially the same. The effect of stimulation signals such as voltage, and current, on the bending angle and displacement is also studied using square wave potential. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. RP Wang, HL (reprint author), Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. NR 19 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5302-1 J9 P SOC PHOTO-OPT INS PY 2004 VL 5385 BP 406 EP 412 DI 10.1117/12.537978 PG 7 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Polymer Science SC Engineering; Instruments & Instrumentation; Polymer Science GA BAS49 UT WOS:000223368700046 ER PT S AU Massad, JE Sumali, H Chaplya, PM Martin, JW AF Massad, JE Sumali, H Chaplya, PM Martin, JW BE Smith, RC TI Deflection model for corner-supported plates with segmented in-plane actuators SO SMART STRUCTURES AND MATERIALS 2004: MODELING, SIGNAL PROCESSING, AND CONTROL SE Proceedings of SPIE LA English DT Proceedings Paper CT Smart Structures and Materials 2004 Conference CY MAR 15-18, 2004 CL San Diego, CA SP SPIE, Amer Inst Aeronaut & Astronaut, Amer Soc Mech Engineers, Soc Expt Mech, Boeing Co, Journal Intelligent Mat Syst & Struct, Rhombus Consultants Grp, CSA Engn Inc, ISIS Canada DE corner supports; PVDF laminate; rectangular plate; shape control ID ACTIVE SHAPE CONTROL; PIEZOELECTRIC ACTUATORS; APERTURE ANTENNAS; MIRROR; REFLECTORS; MEMBRANE; DESIGN AB The shape control of flexible mirrors has been studied mainly for edge-supported thin-plate configurations. For applications such as optical reflectors, corner-supported configurations, which allow for paraboloidal geometries, prove more applicable. Moreover, the use of corner supports enables more flexibility and larger achievable deflections than with edge supports. This paper discusses a corner-supported thin rectangular plate actuated by a two-dimensional array of segmented piezoelectric laminated actuators. First, a model determining the deflected shape of a laminate for a given distribution of voltages over the actuator array is derived. Second, the results of the model are shown to agree well with a finite element simulation of the structure. Finally, paraboloidal deflection of a rectangular PVDF laminate is investigated. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM jemassa@sandia.gov NR 28 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5300-5 J9 PROC SPIE PY 2004 VL 5383 BP 309 EP 319 DI 10.1117/12.539832 PG 11 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA BAT29 UT WOS:000223423300031 ER PT S AU Tirumala, VR Mancini, DC Caneba, GT AF Tirumala, VR Mancini, DC Caneba, GT BE Varadan, VK TI Synthesis of ultrafast response smart microgel structures SO SMART STRUCTURES AND MATERIALS 2004: SMART ELECTRONICS, MEMS, BIOMEMS AND NANOTECHNOLOGY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2004 Conference CY MAR 15-18, 2004 CL San Diego, CA SP SPIE, Amer Inst Aeronaut & Astronaut, Amer Soc Mech Engineers, Soc Expt Mech, Boeing Co, Journal Intelligent Mat Syst & Struct, Rhombus Consultants Grp, CSA Engn Inc, ISIS Canada DE microgels; lithography; smart polymers; nanostructure ID PRECIPITATION POLYMERIZATION PROCESS; POLY(N-ISOPROPYLACRYLAMIDE) HYDROGELS; SENSITIVE HYDROGELS AB Hydrogels are "smart" polymers that respond to an external stimulus with a change in their physical characteristics. The response of gel microstructures, or microgels, to an external stimulus depends on their size and synthesis route. Smart microgels based on poly (N-isopropylacrylamide) and poly (methacrylic acid) were prepared by combining the aspects of x-ray lithography and a novel synchrotron-radiation-induced polymerization. The morphology of microgels prepared by this novel synthesis route was characterized by optical and atomic force microscopy to better understand their response properties. Microgels obtained from this method are in a hydrophobic state and are richly nanoporous in their morphology. Average pore size of these gel networks lies within a few hundreds of nanometers as observed from atomic force microscopy. Due to their ultrafast response, these microgel structures can be used as microtransducers that respond to a change in moisture concentration. C1 Argonne Natl Lab, Expt Facil Div, Argonne, IL 60439 USA. RP Tirumala, VR (reprint author), Argonne Natl Lab, Expt Facil Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 26 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5306-4 J9 P SOC PHOTO-OPT INS PY 2004 VL 5389 BP 221 EP 228 DI 10.1117/12.543401 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Materials Science, Multidisciplinary SC Engineering; Instruments & Instrumentation; Materials Science GA BAV21 UT WOS:000223715800025 ER PT S AU Rutherford, AC Park, G Sohn, H Farrar, CR AF Rutherford, AC Park, G Sohn, H Farrar, CR BE Flatau, AB TI Nonlinear feature identification of impedance-based structural health monitoring SO SMART STRUCTURES AND MATERIALS 2004: SMART STRUCTURES AND INTEGRATED SYSTEMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Smart Structures and Materials 2004 Conference CY MAR 15-18, 2004 CL San Diego, CA SP SPIE, Amer Inst Aeronaut & Astronaut, Amer Soc Mech Engineers, Soc Expt Mech, Boeing Co, Journal Intelligent Mat Syst & Struct, Rhombus Consultants Grp, CSA Engn Inc, ISIS Canada DE structural health monitoring; piezoelectric materials; impedance method; nonlinearity AB The impedance-based structural health monitoring technique, which utilizes electromechanical coupling properties of piezoelectric materials, has shown feasibility for use in a variety of structural health monitoring applications. Relying on high frequency local excitations (typically>20 kHz), this technique is very sensitive to minor chances in structural integuity in the near field of piezoelectric sensors. Several damage sensitive features have been identified and used coupled with the impedance methods. Most of these methods are, however, limited to linearity assumptions of a structure. This paper presents the use of experimentally identified nonlinear features, combined with impedance methods, for structural health monitoring. Their applicability to for damage detection in various frequency ranges is demonstrated using actual impedance signals measured from a portal frame structure. The performance of the nonlinear feature is compared with those of conventional impedance methods. This paper reinforces the utility of nonlinear features in structural health monitoring, and suggests that their varying sensitivity in different frequency ranges may be leveraged for certain applications. C1 Los Alamos Natl Lab, Engn Sci & Applicat Weap Response Grp, Los Alamos, NM 87545 USA. RP Rutherford, AC (reprint author), Los Alamos Natl Lab, Engn Sci & Applicat Weap Response Grp, Los Alamos, NM 87545 USA. RI Farrar, Charles/C-6954-2012 NR 10 TC 0 Z9 0 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5307-2 J9 P SOC PHOTO-OPT INS PY 2004 VL 5390 BP 521 EP 531 DI 10.1117/12.540106 PG 11 WC Engineering, Electrical & Electronic; Engineering, Mechanical SC Engineering GA BAV92 UT WOS:000223848600053 ER PT B AU Imbeni, V Mehta, A Robertson, SW Duerig, TW Pelton, AR Ritchie, RO AF Imbeni, V Mehta, A Robertson, SW Duerig, TW Pelton, AR Ritchie, RO BE Pelton, AR Duerig, T TI On the mechanical behavior of Nitinol under multiaxial loading conditions and in situ synchrotron x-ray SO SMST-2003: Proceedings of the International Conference on Shape Memory and Superelastic Technologies LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies (SMST-2003) CY MAY 05-08, 2003 CL Pacific Grove, CA SP Boston Sci, Ft Wayne Met, Johnson Matthey, Shape Mem Applicat, MeKo, Minitubes, Special Met, TiNi Alloy Co, UTI DE Nitinol; multiaxial; torsion; x-ray; synchrotron; Luders bands; R-phase; in situ ID SHAPE-MEMORY; TRANSFORMATION; TENSION; ALLOYS AB Although the use of Nitinol in the biomedical industry has been very successful, it has been difficult to accurately compute stresses via Finite Element Analysis (FEA) due to the presence of complex in vivo loading patterns. Constitutive laws for shape memory alloys (SMA) subjected to multiaxial loading, which are based on direct experimental observations, are generally not available in the literature, and thus FEA models are generally based on uniaxial data. Accordingly, in the present work, tension-torsion tests are conducted on Nitinol thin walled tubes (thickness/radius ratio of 1:10) using various loading/unloading paths under isothermal conditions. The experimental results showed significant variations in the mechanical response along the two loading axes. To fully understand the macroscopic and microscopic aspects of the transformation, in situ multiaxial (tension-torsion) loading experiments were also performed at the Stanford Synchrotron Radiation Laboratory (SSRL) in order to monitor the material's state of transformation and identify the nature, volume fraction of phases present, and the elastic strain in them as a function of stress and stress state. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Imbeni, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 9 TC 1 Z9 1 U1 0 U2 8 PU SMST SOC INC PI MENLO PARK PA C/O SRI M/S AA287, 333 RAVENSWOOD AVENUE, MENLO PARK, CA 94025 USA BN 0-9660508-3-5 PY 2004 BP 267 EP 276 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BCC80 UT WOS:000228663400031 ER PT B AU Robertson, SW Imbeni, V Notkina, E Wenk, HR Ritchie, RO AF Robertson, SW Imbeni, V Notkina, E Wenk, HR Ritchie, RO BE Pelton, AR Duerig, T TI Texture in tubes and plates of Nitinol SO SMST-2003: Proceedings of the International Conference on Shape Memory and Superelastic Technologies LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies (SMST-2003) CY MAY 05-08, 2003 CL Pacific Grove, CA SP Boston Sci, Ft Wayne Met, Johnson Matthey, Shape Mem Applicat, MeKo, Minitubes, Special Met, TiNi Alloy Co, UTI DE Nitinol; texture; x-ray diffraction; pole figures ID TENSION; STRAIN AB The superelastic/shape memory material, Nitinol, a roughly equiatomic alloy of Ni and Ti, rapidly is becoming one of the most important metallic implant materials in the biomedical industry, in particular for the manufacture of endovascular stents. As such stents invariably are laser machined from Nitinol tubes (or sheets rolled into tubes), it is important to understand fully the physical phenomena that may affect the mechanical behavior of this material. With tubing and sheet, one major issue is crystallographic texture, which can play a key role in influencing the mechanical properties of Nitinol. In this paper, we present a preliminary study on how geometry and heat treatment can affect the texture of Nitinol. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Robertson, SW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 13 TC 1 Z9 1 U1 0 U2 0 PU SMST SOC INC PI MENLO PARK PA C/O SRI M/S AA287, 333 RAVENSWOOD AVENUE, MENLO PARK, CA 94025 USA BN 0-9660508-3-5 PY 2004 BP 341 EP 347 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BCC80 UT WOS:000228663400039 ER PT B AU Shabalovskaya, S Anderegg, J Rondelli, G Xiong, JP AF Shabalovskaya, S Anderegg, J Rondelli, G Xiong, JP BE Pelton, AR Duerig, T TI The effect of surface particulates on the corrosion resistance of nitinol wire SO SMST-2003: Proceedings of the International Conference on Shape Memory and Superelastic Technologies LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies (SMST-2003) CY MAY 05-08, 2003 CL Pacific Grove, CA SP Boston Sci, Ft Wayne Met, Johnson Matthey, Shape Mem Applicat, MeKo, Minitubes, Special Met, TiNi Alloy Co, UTI DE Nitinol; corrosion resistance; cyclic potentiodynamic; potentiostatic polarization; inclusions ID SHAPE-MEMORY ALLOY; BOILING WATER; BEHAVIOR; NI AB Corrosion resistance is an important property for the long-term stability and biocompatibility of implants and medical devices, yet past studies indicate relatively high inconsistency. The present study is aimed at exploring the nature of this inconsistency in Nitinol and the nature of corrosion improvement upon corrosion testing. Using corrosion tests, in combination with a study of surface morphology, it is shown that the surface concentration of foreign particles (inclusions and mechanically imbedded particles) may be an important factor in the control of Nitinol corrosion resistance. Surface treatments, potential sweeping, and abrupt potential excursions help in the removal of these surface particles and provide better corrosion resistance. The nature of particles was explored using Auger and Energy-Dispersive X-ray Spectrum (EDXS) analysis. C1 Iowa State Univ, Inst Phys Res & Technol, Ames, IA 50011 USA. RP Shabalovskaya, S (reprint author), Iowa State Univ, Inst Phys Res & Technol, Ames, IA 50011 USA. NR 19 TC 2 Z9 2 U1 1 U2 4 PU SMST SOC INC PI MENLO PARK PA C/O SRI M/S AA287, 333 RAVENSWOOD AVENUE, MENLO PARK, CA 94025 USA BN 0-9660508-3-5 PY 2004 BP 399 EP 408 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BCC80 UT WOS:000228663400046 ER PT B AU Vestel, MJ Grummon, DS AF Vestel, MJ Grummon, DS BE Pelton, AR Duerig, T TI Inhomogeneous microstructures observed in crystallized NiTi films SO SMST-2003: Proceedings of the International Conference on Shape Memory and Superelastic Technologies LA English DT Proceedings Paper CT International Conference on Shape Memory and Superelastic Technologies (SMST-2003) CY MAY 05-08, 2003 CL Pacific Grove, CA SP Boston Sci, Ft Wayne Met, Johnson Matthey, Shape Mem Applicat, MeKo, Minitubes, Special Met, TiNi Alloy Co, UTI DE thin films; nitinol; cystallization; microstructure; amorphous ID SPUTTERED THIN-FILMS; TI-X(NI,CU)(1-X); TRANSFORMATIONS; DEPOSITION; KINETICS; TINI AB Crystalline thin films of nickel-titanium (NiTi) are known to possess superelastic properties and display a robust shape memory effect (SME) - qualities useful for developing MEMS sensors and actuators. However, the high temperature and cooldown required for the direct deposition of crystalline NiTi films can cause extrinsic residual stress and, ultimately, catastrophic delamination. Prevention of delamination can be achieved, especially for thick films (> 5 micrometers); the amorphous form of NiTi is sputter deposited at a low temperature, patterned and etched, released, and then crystallized to develop the proper microstructure. Here we report some results of a study that examined the crystallization process using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The minimum temperature for complete crystallization in a reasonable length of time was found to be about 400 degrees C. Crystalline grains always nucleated first at the surface, rapidly grew laterally until impingement, and then continued to grow inward to form columnar grains as the parent amorphous phase was consumed. Surface roughness delayed the onset of surface nucleation. For very smooth surfaces, crystallization of columnar grains nucleated quickly; after lateral impingement, growth inward was apparently more sluggish. Multiple DSC exotherms observed in these films suggest additional nucleation events may have occurred. TEM micrographs illustrate these secondary nucleation events resulted in distinct microstructual layers, perfectly stratified in the plane of the film, with single grain aspect ratios that are radically different from those of surface nucleated columnar grains. These interior, wide, flat grains are shown to nucleate independently in the bulk and result from different kinetic parameters. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Lab Ultra Small Technol Engn & Res, Berkeley, CA 94720 USA. RP Vestel, MJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Lab Ultra Small Technol Engn & Res, Berkeley, CA 94720 USA. NR 32 TC 0 Z9 0 U1 0 U2 1 PU SMST SOC INC PI MENLO PARK PA C/O SRI M/S AA287, 333 RAVENSWOOD AVENUE, MENLO PARK, CA 94025 USA BN 0-9660508-3-5 PY 2004 BP 701 EP 712 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BCC80 UT WOS:000228663400077 ER PT S AU Reason, LL AF Reason, LL BE Alvard, MS TI The behavioral ecology of female genital cutting in Northern Ghana SO SOCIOECONOMIC ASPECTS OF HUMAN BEHAVIORAL ECOLOGY SE RESEARCH IN ECONOMIC ANTHROPOLOGY LA English DT Proceedings Paper CT 101st Annual Meeting of the American-Anthropological-Association CY NOV 20-24, 2002 CL NEW ORLEANS, LA SP Amer Anthropol Assoc ID CIRCUMCISION; FERTILITY; MARRIAGE; CONSEQUENCES AB For decades, researchers studying female genital cutting have sought to understand why the practice continues amidst abundant evidence indicating that serious health consequences can result from the more aggressive forms of cutting. Behavioral ecology theory is applied to data collected among Ghana's Kassena-Nankana to highlight the gendered cultural forces that keep FGC practice in place through successful reproductive outcomes. With its strong association to marriageability, and thus women's status and access to resources through marriage, circumcision has long been obligatory. However, the social transformation that is currently underway in this rural population is bringing a new perspective to the value of education, which is replacing circumcision as the resource access currency. C1 Battelle Seattle Res Ctr, Seattle, WA USA. NR 59 TC 5 Z9 5 U1 0 U2 0 PU JAI-ELSEVIER SCI BV PI AMSTERDAM PA RADARWEG 29, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0190-1281 BN 0-7623-1082-0 J9 RES ECON AN PY 2004 VL 23 BP 175 EP 202 DI 10.1016/S0190-1281(04)23007-4 PG 28 WC Anthropology SC Anthropology GA BBK76 UT WOS:000225912200008 ER PT S AU Gorton, I Haack, J McGee, D Cowell, A Kuchar, O Thomson, J AF Gorton, I Haack, J McGee, D Cowell, A Kuchar, O Thomson, J BE Lucena, C Garcia, A Romanovsky, A Castro, J Alencar, P TI Evaluating agent architectures: Cougaar, aglets and AAA SO SOFTWARE ENGINEERING FOR MULTI-AGENT SYSTEMS II: RESEARCH ISSUES AND PRACTICAL APPLICATIONS SE LECTURE NOTES IN COMPUTER SCIENCE LA English DT Article; Proceedings Paper CT 2nd International Workshop on Software Engineering for Large-Scale Multi-Agent Systems CY MAY 07, 2003 CL Portland, OR AB Research and development organizations are constantly evaluating new technologies in order to implement the next generation of advanced applications. At Pacific Northwest National Laboratory, agent technologies are perceived as an approach that can provide a competitive advantage in the construction of highly sophisticated software systems in a range of application areas. To determine the sophistication, utility, performance, and other critical aspects of such systems, a project was instigated to evaluate three candidate agent toolkits. This paper reports on the outcomes of this evaluation, the knowledge accumulated from carrying out this project, and provides insights into the capabilities of the agent technologies evaluated. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gorton, I (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Gorton, Ian/A-8247-2009 NR 13 TC 7 Z9 7 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0302-9743 BN 3-540-21182-9 J9 LECT NOTES COMPUT SC PY 2004 VL 2940 BP 264 EP 278 PG 15 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA BY86W UT WOS:000189482500015 ER PT J AU Devine, WD Mullen, MD Tyler, DD Houston, AE Joslin, JD Hodges, DG Tolbert, VR Walsh, ME AF Devine, WD Mullen, MD Tyler, DD Houston, AE Joslin, JD Hodges, DG Tolbert, VR Walsh, ME TI Conversion from a sycamore biomass crop to a no-till corn system: Effects on soils SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID ORGANIC-MATTER; DRY COMBUSTION; NITROGEN; CARBON; DECOMPOSITION; AVAILABILITY; WATER; PLANTATIONS; STORAGE; EROSION AB Agricultural lands may be used to produce short-rotation woody crops (SRWCs) for fuel or fiber, but the effects of SRWCs on soils are poorly understood. In this study, a SRWC was integrated with an annual row crop system in a row crop-SRWC-row crop rotation. The objective was to document the effects of the woody crop on soil total C, N, inorganic N, and aggregate stability after the site was returned to row crop production. Soybean [Glycine max (L.) Merr.] was followed by 4- and 5-yr rotations of American sycamore (Platanus occidentalis L.), followed by no-till corn (Zea mays L.) (SY4C and SY5C, respectively). Continuous row crops (soybean converted to corn) served as a control (SBC). Four rates of broadcast NH4NO3 were applied to corn. The study was in southwestern Tennessee on a Memphis-Loring silt loam intergrade (fine-silty, mixed, active, thermic Typic Hapludalfs-rine-silty, mixed, active, thermic Oxyaquic Fragiudalfs). During 3 yr of post-sycamore corn production, increases in soil total C concentration below a 2.5-cm depth were attributed to the sycamore crop. After fertilization of first-year corn at 73 and 146 kg N ha(-1), soil inorganic N concentrations were lower in the SY4C than the SBC system from 0 to 2.5 cm. Mean weight diameter (MWD) of water-stable soil aggregates at depths of 2.5 to 15 cm was greater for the SY4C than the SBC system. Four- and 5-yr sycamore rotations significantly affected chemical and physical properties of an agricultural soil. C1 US Forest Serv, Olympia Forestry Sci Lab, USDA, PNW Res Stn, Olympia, WA 98512 USA. Univ Kentucky, Dept Agron, Lexington, KY 40546 USA. Univ Tennessee, W Tennessee Expt Stn, Jackson, TN 38301 USA. Univ Tennessee, Grand Junction, TN 38039 USA. Belowground Forest Res, Oak Ridge, TN 37830 USA. Univ Tennessee, Dept Forestry Fisheries & Wildlife, Knoxville, TN 37901 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Devine, WD (reprint author), US Forest Serv, Olympia Forestry Sci Lab, USDA, PNW Res Stn, 3625 93rd Ave SW, Olympia, WA 98512 USA. EM wdevine@ts.fed.us OI Hodges, Donald/0000-0001-6751-0927 NR 36 TC 4 Z9 5 U1 1 U2 5 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD JAN-FEB PY 2004 VL 68 IS 1 BP 225 EP 233 PG 9 WC Soil Science SC Agriculture GA 767WV UT WOS:000188497600028 ER PT J AU Johnson, WH Buck, BJ Brogonta, H Brock, AL AF Johnson, WH Buck, BJ Brogonta, H Brock, AL TI Variations in depleted uranium sorption and solubility with depth in arid soils SO SOIL & SEDIMENT CONTAMINATION LA English DT Article DE distribution coefficient; sequential extraction; leaching; depleted uranium; uranium; sorption; DU penetrators ID SEQUENTIAL EXTRACTION; ACTINIDE AB This study examined the ability of alkaline desert soils to sorb depleted uranium (DU) as a function of soil horizon and assessed the solubility of corrosion and migration products from two DU kinetic energy penetrators exposed on the desert surface for a 22-y period. Both uranium corrosion products on the surface, and subsurface uranium originating from the dissolution of surface corrosion products followed by reprecipitation or sorption, were examined. A four-step sequential extraction method was used to classify titanium solubility at each site. Results show that distribution coefficient for uranium is highly variable, but can be correlated with the clay content (r = 0.55) and soil pH (r = 0.73) of the soil horizon considered. Surface corrosion products and near-surface uranium easily dissolve in a weak acid solution (25% acetic acid for two hours), suggesting a uranyl hydroxide form. As uranium migrates beyond several centimeters in depth, it forms insoluble aggregates with silicate minerals and requires strong acids to leach it. The formation of uranium-silicate mineral aggregates appears to be the limiting factor in vertical vadose zone transport of DU at the site investigated. C1 Univ Nevada, Las Vegas, NV 89557 USA. RP Johnson, WH (reprint author), Los Alamos Natl Lab, MSJ514, Los Alamos, NM 87545 USA. EM william@lanl.gov NR 18 TC 16 Z9 16 U1 1 U2 6 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1532-0383 J9 SOIL SEDIMENT CONTAM JI Soil. Sediment. Contam. PY 2004 VL 13 IS 6 BP 533 EP 544 DI 10.1080/15320380490897641 PG 12 WC Environmental Sciences SC Environmental Sciences & Ecology GA 872XI UT WOS:000225242300002 ER PT J AU Cheng, JJ Hlohowskyj, I Tsao, CL AF Cheng, JJ Hlohowskyj, I Tsao, CL TI Ecological risk assessment of radiological exposure to depleted uranium in soils at a weapons testing facility SO SOIL & SEDIMENT CONTAMINATION LA English DT Article DE depleted uranium; ecological risk assessment; ecological dose modeling; radiation exposure; biota dose limits AB The potential for unacceptable risks to biota from radiological exposure to depleted uranium (DU) in soils was evaluated at two sites where DU weapons testing had been conducted in the past. A screening risk assessment was conducted to determine if measured concentrations of DU-associated radionuclides in site soils exceed radionuclide levels considered protective of biota. While concentrations of individual radionuclides did not exceed acceptable levels, total radionuclide concentrations could result in potentially unacceptable closes to exposed biota. Thus, a receptor-specific assessment was conducted to estimate external and internal radiological doses to vegetation and wildlife known or expected to occur at the sites. Wildlife evaluated included herbivores, omnivores, and top-level predators. Internal dose estimates to wildlife considered exposure via fugitive dust inhalation and soil and food ingestion; root uptake was the primary exposure route evaluated for vegetation. Total doses were compared with acceptable dose levels of 1.0 and 0.1 rad/day for vegetation and wildlife, respectively, with potentially unacceptable risks indicated for doses exceeding these levels. All estimated doses were below or approximated acceptable levels, typically by an order of magnitude or more. These results indicate that current levels of DU in soils do not pose unacceptable radiological risks to biota at the sites evaluated. C1 Argonne Natl Lab, Environm Assessment Div, Argonne, IL 60439 USA. RP Hlohowskyj, I (reprint author), Argonne Natl Lab, Environm Assessment Div, 9700 S Cass Ave, Argonne, IL 60439 USA. EM hlohowskyj@anl.gov NR 27 TC 3 Z9 3 U1 0 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 1532-0383 J9 SOIL SEDIMENT CONTAM JI Soil. Sediment. Contam. PY 2004 VL 13 IS 6 BP 579 EP 595 DI 10.1080/15320380490897678 PG 17 WC Environmental Sciences SC Environmental Sciences & Ecology GA 872XI UT WOS:000225242300005 ER PT J AU Perez, R Burtis, L Hoff, T Swanson, S Herig, C AF Perez, R Burtis, L Hoff, T Swanson, S Herig, C TI Quantifying residential PV economics in the US - payback vs cash flow determination of fair energy value SO SOLAR ENERGY LA English DT Article; Proceedings Paper CT Annual Conference of the American-Solar-Energy-Society (ASES) CY JUN 21-23, 2003 CL Austin, TX SP Amer Solar Energy Soc DE economics; photovoltaics; residential; effective capacity; utility AB Payback is often used as a measure of profitability by prospective PV owners. Contrasting this measure with another financial gauge-life-cycle cash flow-the paper discusses why payback may not be the most appropriate measure for residential PV applications and why it may hide sound financial opportunities for those deciding to invest in a PV system. In parallel, the paper addresses another aspect of economic feasibility: the value of energy produced. For residential applications, this value is currently set at residential net-metered retail rates. We present preliminary evidence that a higher value, reflective of the local effective capacity of PV ought to be claimed for residential PV applications. (C) 2004 Elsevier Ltd. All rights reserved. C1 SUNY Albany, CESTM, ASRC, Albany, NY 12203 USA. Solar Works, Delmar, NY 12054 USA. Clean Power Res, Napa, CA 94558 USA. Pace Univ, Burlington, VT 05406 USA. NREL, Golden, CO 80401 USA. RP Perez, R (reprint author), SUNY Albany, CESTM, ASRC, 251 FUller Rd, Albany, NY 12203 USA. EM perez@asrc.cestm.albany.edu; antanana@yahoo.com; tomhoff@clean-power.com; samswanson@aol.com; christy_he-rig@nrel.gov NR 6 TC 22 Z9 22 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 77 IS 4 BP 363 EP 366 DI 10.1016/j.solener.2004.03.004 PG 4 WC Energy & Fuels SC Energy & Fuels GA 867MU UT WOS:000224847500003 ER PT J AU Perez, R Ineichen, P Kmiecik, M Moore, K Renne, D George, R AF Perez, R Ineichen, P Kmiecik, M Moore, K Renne, D George, R TI Producing satellite-derived irradiances in complex arid terrain SO SOLAR ENERGY LA English DT Article; Proceedings Paper CT Annual Conference of the American-Solar-Energy-Society (ASES) CY JUN 21-23, 2003 CL Austin, TX SP Amer Solar Energy Soc AB This paper describes a methodology to correct satellite-derived irradiances over complex terrain for models that use the visible satellite channel as main input for cloud index determination. Complex terrain is characterized by high reflectance surface and or the juxtaposition of high and low reflectance surfaces (e.g., desert plains and forested ridges). The correction consists of (1) climate dependent post-model clear sky calibration and (2) singularity identification and removal. (C) 2004 Elsevier Ltd. All rights reserved. C1 SUNY Albany, CESTM, ASRC, Albany, NY 12203 USA. Univ Geneva, CUEPE, CH-1227 Carouge, Switzerland. IED, Albany, NY 12203 USA. NREL, Golden, CO 80401 USA. RP Perez, R (reprint author), SUNY Albany, CESTM, ASRC, 251 Fuller Rd, Albany, NY 12203 USA. EM perez@asrc.cestm.albany.edu; pierre.ineichen@cuepe.unige.ch; moore@iedat.com; drenne@nrel.nrel.gov; ray_george@nrel.nrel.gov NR 6 TC 27 Z9 27 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 77 IS 4 BP 367 EP 371 DI 10.1016/j.solener.2003.12.016 PG 5 WC Energy & Fuels SC Energy & Fuels GA 867MU UT WOS:000224847500004 ER PT J AU Burch, J Christensen, C Salasovich, J Thornton, J AF Burch, J Christensen, C Salasovich, J Thornton, J TI Simulation of an unglazed collector system for domestic hot water and space heating and cooling SO SOLAR ENERGY LA English DT Article; Proceedings Paper CT Annual Conference of the American-Solar-Energy-Society (ASES) CY JUN 21-23, 2003 CL Austin, TX SP Amer Solar Energy Soc AB This paper details modeling assumptions and simulation results for an unglazed collector system supplying domestic hot water, space heating, and space cooling loads. Collectors are modeled using unglazed collector test results. Variation of savings with collector area, storage volume, heat exchanger size, and wind for the Albuquerque, NM climate are shown. Over the storage-to-collector ratio range of 40-640 l/m(2) collector, annual savings varies only +/-15%. Cooling is sensitive to heat exchanger size, and heating is sensitive to wind velocity. At a collector area of 23 m(2) the unglazed system meets about 56% of the annual total energy demand, saving 25.9 $/m(2) yr for an all-electric home. For the 23 m(2) area, savings for a cold/damp (Madison) and a hot/humid (Miami) climate are 64% and 56%, respectively, of the savings in Albuquerque. (C) 2004 Elsevier Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Thermal Energy Simulat Specialists Inc, Madison, WI 53719 USA. RP Burch, J (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM jay_burch@nrel.gov; craig_christensen@nrel.gov; james_salasovich@nrel.gov; thornton@tess-inc.com NR 7 TC 6 Z9 7 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 77 IS 4 BP 399 EP 406 DI 10.1016/j.solener.2003.12.014 PG 8 WC Energy & Fuels SC Energy & Fuels GA 867MU UT WOS:000224847500008 ER PT J AU Bhattacharya, RN Ramanathan, K AF Bhattacharya, RN Ramanathan, K TI Cu(In,Ga)Se-2 thin film solar cells with buffer layer alternative to CdS SO SOLAR ENERGY LA English DT Article DE copper indium gallium diselenide; chemical bath deposition (CIGS); ZnS(O,OH); CdS; Zn AB Progress in fabricating Cu(In,Ga)Se-2 (CIGS) solar cells with ZnS(O,OH) buffer layers prepared by chemical bath deposition (CBD) is discussed in this paper. Such buffer layers could potentially replace US in the CIGS solar cell. Total-area conversion efficiency of up to 18.6% has been reported previously using ZnS(O,OH) prepared by CBD. The reported 100 nm CBD ZnS(O,OH) layer was prepared by at least three consecutive depositions, which would make it a relatively expensive replacement for CdS. The recent development of a ZnS(O,OH) layer that enabled to obtain high-efficiency devices using a single-layer CBD is reported in this paper. A 14.4%-efficient device is obtained by using one-layer CBD ZnS(O,OH) on commercial-grade Shell Solar Cu(In,Ga)(S,Se)(2) (CIGSS) absorber and an up to 17.4% device is obtained by using two-layer CBD ZnS(O,OH) on an NREL CIGS absorber. (C) 2004 Elsevier Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Bhattacharya, RN (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM raghu_bhattacharya@nrel.gov NR 7 TC 46 Z9 47 U1 2 U2 36 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 77 IS 6 BP 679 EP 683 DI 10.1016/j.solener.2004.05.009 PG 5 WC Energy & Fuels SC Energy & Fuels GA 883RY UT WOS:000226034600003 ER PT J AU Wu, XZ AF Wu, XZ TI High-efficiency polycrystalline CdTe thin-film solar cells SO SOLAR ENERGY LA English DT Article DE CdTe; thin-film; high-efficiency ID CADMIUM STANNATE; CDS AB Cadmium telluride is a promising photovoltaic material for thin-film solar cells. However, further improvements on performance and reproducibility of devices have been limited by the conventional SnO2/poly-CdS/poly-CdTe device structure used for more than 30 years. In this paper, we review partial R&D approaches at NREL to understand the issues related to the conventional device structure and to develop several novel materials and a modified device structure for minimizing these issues. We have achieved a CdTe polycrystalline thin-film solar cell demonstrating an NREL-confirmed, total-area efficiency of 16.5% by using new materials and the modified device structure. To apply the high-efficiency CdTe cell fabrication technique, we developed two manufacturing processes for producing high-efficiency CdTe modules with the potential of high throughput and low cost. (C) 2004 Elsevier Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wu, XZ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM xuanzhi_wu@nrel.gov NR 24 TC 391 Z9 405 U1 21 U2 198 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 77 IS 6 BP 803 EP 814 DI 10.1016/j.solener.2004.06.006 PG 12 WC Energy & Fuels SC Energy & Fuels GA 883RY UT WOS:000226034600016 ER PT J AU Mahan, AH AF Mahan, AH TI Solar cell research and development using the hot wire CVD process SO SOLAR ENERGY LA English DT Article DE hot wire CVD; amorphous silicon; microcrystalline silicon; deposition site; Staebler-Wronski effect; large area deposition ID CHEMICAL-VAPOR-DEPOSITION; MICROCRYSTALLINE SILICON; AMORPHOUS-SILICON; DEVICE-QUALITY; HIGH-RATES; FILMS; HWCVD; JAPAN; 1ST AB This article reviews the research and development of solar cells fabricated using the hot wire CVD (HWCVD) process. A short history of the technique is given, and the advantages of this deposition technique as they relate to solar cell fabrication are quantified. A chronological history of solar cell fabrication involving three major research groups, with a long history in HWCVD solar cell fabrication, is then given, as such histories illustrate the evolution of solar cell research involving HWCVD. Illustrative examples of activities of new research groups entering this field are then discussed, and the outlook for this field is given. (C) 2004 Elsevier Ltd. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mahan, AH (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM harv_mahan@nrel.gov NR 40 TC 3 Z9 3 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 77 IS 6 BP 931 EP 938 DI 10.1016/j.solener.2004.06.008 PG 8 WC Energy & Fuels SC Energy & Fuels GA 883RY UT WOS:000226034600028 ER PT J AU Macdonald, DH Cuevas, A Kerr, MJ Samundsett, C Ruby, D Winderbaum, S Leo, A AF Macdonald, DH Cuevas, A Kerr, MJ Samundsett, C Ruby, D Winderbaum, S Leo, A TI Texturing industrial multicrystalline silicon solar cells SO SOLAR ENERGY LA English DT Article; Proceedings Paper CT Solar World Congress CY NOV 25-DEC 02, 2001 CL ADELAIDE, AUSTRALIA SP Int Solar Energy Soc AB Three potential techniques for texturing commercial multicrystalline silicon solar cells are compared on the basis of reflectance measurements. Wet acidic texturing, which would be the least costly to implement, produces a modest improvement in reflection before antireflection coating and encapsulation, whereas maskless reactive-ion etching texturing, and especially masked reactive-ion etched `pyramids', generate a larger gain in absorption. After antireflection coating and encapsulation however, the differences between the methods are reduced. Short-circuit current measurements on wet acidic textured cells reveal that there is a significant additional current gain above that expected from the reduced reflection. This is attributed to both light-trapping and oblique coupling of incident light into the cell, resulting in generation closer to the junction. (C) 2003 Elsevier Ltd. All rights reserved. C1 Australian Natl Univ, FEIT, Dept Engn, Acton, ACT 0200, Australia. Sandia Natl Labs, Albuquerque, NM 87185 USA. BPSolar, Homebush Bay, NSW, Australia. RP Macdonald, DH (reprint author), Australian Natl Univ, FEIT, Dept Engn, Acton, ACT 0200, Australia. EM daniel.macdonald@anu.edu.au RI Macdonald, Daniel/A-3794-2008; Cuevas, Andres/K-3499-2014 NR 4 TC 140 Z9 155 U1 6 U2 52 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 76 IS 1-3 SI SI BP 277 EP 283 DI 10.1016/j.solener.2003.08.019 PG 7 WC Energy & Fuels SC Energy & Fuels GA 766TL UT WOS:000188391600037 ER PT J AU Schlegel, GO Burkholder, FW Klein, SA Beckman, WA Wood, BD Muhs, JD AF Schlegel, GO Burkholder, FW Klein, SA Beckman, WA Wood, BD Muhs, JD TI Analysis of a full spectrum hybrid lighting system SO SOLAR ENERGY LA English DT Article DE lighting; concentrator; thermal photovoltaics; building simulation; economics; optical fiber AB Hybrid lighting is a new approach to lighting that integrates light from natural and electric sources. A two-axis tracking concentrator collects beam radiation which is reflected onto a mirror that divides the solar radiation into infrared and visible spectra. The visible light is distributed through optical fibers and combined with fluorescent lighting in specially designed luminaires. The infrared portion of the spectrum is used to generate electricity using a thermal photovoltaic array. A simulation of a hybrid lighting system has been created using the TRNSYS transient simulation program. The simulation incorporates the spectral properties of the hybrid lighting components as well as the spectral distribution of the incoming solar radiation that is based upon output from the SMARTS atmospheric transmittance model. An office building model is coupled with the hybrid lighting simulation to predict the annual energy impact upon lighting, heating, and cooling loads. Simulations were performed in six locations within the United States. Hybrid lighting systems performed best in Honolulu, HI and Tucson, AZ justifying system capital costs of $2410 and $1995 per module, respectively, based on a 10 year payback period. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Wisconsin, Solar Energy Lab, Madison, WI 53705 USA. Univ Nevada, Dept Mech Engn, Reno, NV 89557 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Beckman, WA (reprint author), Univ Wisconsin, Solar Energy Lab, 1500 Engn Dr, Madison, WI 53705 USA. EM beckman@engr.wisc.edu NR 11 TC 30 Z9 33 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 76 IS 4 BP 359 EP 368 DI 10.1016/j.solener.2003.11.005 PG 10 WC Energy & Fuels SC Energy & Fuels GA 803OS UT WOS:000220241000001 ER PT J AU Reda, I Andreas, A AF Reda, I Andreas, A TI Solar position algorithm for solar radiation applications SO SOLAR ENERGY LA English DT Article DE global solar irradiance; solar zenith angle; solar azimuth angle; VSOP87 theory; universal time Delta UT1 AB There have been many published articles describing solar position algorithms for solar radiation applications. The best uncertainty achieved in most of these articles is greater than +/-0.01degrees in calculating the solar zenith and azimuth angles. For some, the algorithm is valid for a limited number of years varying from 15 years to a hundred years. This report is a step by step procedure for implementing an algorithm to calculate the solar zenith and azimuth angles in the period from the year -2000 to 6000, with uncertainties of +/-0.0003degrees. The algorithm is described in a book written by Jean Mecus in 1998. This report is written in a step by step format to simplify the complicated steps described in the book, with a focus on the sun instead of the planets and stars in general. It also introduces some changes to accommodate for solar radiation applications. The changes include changing the direction of measuring azinluth angles to be measured from north and eastward instead of being measured from South and eastward, and the direction of measuring the observer's geographical longitude to be measured as positive eastward from Greenwich meridian instead of negative. This report also includes the calculation of incidence angle for a surface that is tilted to any horizontal and vertical angle, as described by Iqbals in 1983. (C) 2003 Elsevier Ltd. All rights reserved. C1 NREL, Golden, CO 80401 USA. RP Reda, I (reprint author), NREL, 1617 Cole Blvd, Golden, CO 80401 USA. EM ibrahim_reda@nrel.gov NR 5 TC 177 Z9 197 U1 2 U2 27 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-092X J9 SOL ENERGY JI Sol. Energy PY 2004 VL 76 IS 5 BP 577 EP 589 DI 10.1016/j.solener.2003.12.003 PG 13 WC Energy & Fuels SC Energy & Fuels GA 804QY UT WOS:000220314400004 ER PT S AU Keller, CF AF Keller, CF BE Pap, JM Kuhn, J Labitzke, K Shea, MA TI 1000 years of climate change SO SOLAR VARIABILITY AND CLIMATE CHANGE SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE climate change; 1000 years of climate change; solar activity; solar forcing ID MEDIEVAL WARM PERIOD; 11-YEAR SOLAR-CYCLE; COSMIC-RAYS; TEMPERATURE VARIABILITY; LAST MILLENNIUM; EARTHS CLIMATE; SUNSPOT CYCLE; ICE-AGE; IRRADIANCE; CENTURIES AB The magnitude of solar forcing varies with the amount of solar activity. In addition to the 10-12 year variations, solar activity varies over centennial and millenial periods. During the past 1000 years, of particular interest were the Medieval Warming Period (high solar activity), the Maunder Minimum, (minimal solar activity) and the sharp multi-decadal increase in solar maxima during the first half of the 20th Century. Satellite observations of solar irradiance for the past two decades have allowed calibration of variations in solar activity proxies. A number of attempts at reconstructing past climate variations via these proxies has shown that direct (irradiance) solar forcing can explain observed northern hemisphere temperatures from 1000 to 1900, but fails to account for most of the observed warming in the past 100 years, especially after 1975. Because solar direct forcing is able to account for climate changes prior to 1900, indirect solar forcing effects seem to be small, but merit continued study especially until both paleo-temperatures and magnitude of forcings are known more precisely. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Inst Geophys & Planetary Phys, Los Alamos, NM 87545 USA. RP Keller, CF (reprint author), Los Alamos Natl Lab, Inst Geophys & Planetary Phys, MS C305, Los Alamos, NM 87545 USA. EM cfk@lanl.gov NR 63 TC 6 Z9 7 U1 6 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2004 VL 34 IS 2 BP 315 EP 322 DI 10.1016/j.asr.2004.01.020 PG 8 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BAS51 UT WOS:000223368900016 ER PT J AU Saito, S Umemoto, K Louie, SG Cohen, ML AF Saito, S Umemoto, K Louie, SG Cohen, ML TI Energetics and structural stability of Cs3C60 SO SOLID STATE COMMUNICATIONS LA English DT Article DE fullerenes; high-T-c superconductors; nanostructures; crystal structure and symmetry ID LOCAL-DENSITY APPROXIMATION; DOPED C-60; ELECTRONIC-PROPERTIES; SUPERCONDUCTIVITY; PHASE; PSEUDOPOTENTIALS; FULLERIDES; CARBON; FORM; GAS AB Using the ab initio pseudopotential total-energy method and the density-functional theory, we study the energetics of face-centered-cubic Cs3C60 which is a material of great interest as a possible high transition-temperature superconductor. At the optimized lattice constant the volume per C-60 is found to be smaller than the the most-stable hexagon-coordination A15 phase, while the total energy of the fcc phase is about 0.9 eV higher than the At 5 phase. These results indicate that a low-temperature and high-pressure synthesis method might be a possible way to produce the fcc Cs3C60 phase. In addition, it is also found that the A15 Cs3C60 should show a phase transformation from a hexagon-coordination phase to a pentagon-coordination phase under hydrostatic pressure. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. RP Saito, S (reprint author), Univ Calif Berkeley, Dept Phys, 366 Le Conte Hall 7300, Berkeley, CA 94720 USA. EM saito@civet.berkeley.edu NR 32 TC 11 Z9 11 U1 2 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PY 2004 VL 130 IS 5 BP 335 EP 339 DI 10.1016/j.ssc.2004.02.011 PG 5 WC Physics, Condensed Matter SC Physics GA 813EN UT WOS:000220890500010 ER PT J AU Petkov, V Qadir, D Shastri, SD AF Petkov, V Qadir, D Shastri, SD TI Rapid structure determination of disordered materials: study of GeSe2 glass SO SOLID STATE COMMUNICATIONS LA English DT Article DE GeSe2; X-ray scattering; glass structure ID X-RAY-DIFFRACTION; SCATTERING; REFINEMENT; PROGRAM; ORDER AB X-ray diffraction experiments on GeSe2 glass employing an imaging Plate detector system have been carried out and their performance compared to that of traditional experiments employing point-type detectors. Imaging Plate detectors have been found to perform very well delivering good quality data for just a second. The analysis of the experimental data shows that the atomic ordering in GeSe2 glass bears many of the characteristics of a random network of Ge-Se-4 tetrahedra. (C) 2003 Elsevier Ltd. All rights reserved. C1 Cent Michigan Univ, Dept Phys, Mt Pleasant, MI 48859 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Petkov, V (reprint author), Cent Michigan Univ, Dept Phys, Dow 203, Mt Pleasant, MI 48859 USA. NR 15 TC 19 Z9 19 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JAN PY 2004 VL 129 IS 4 BP 239 EP 243 DI 10.1016/j.ssc.2003.10.007 PG 5 WC Physics, Condensed Matter SC Physics GA 759NA UT WOS:000187742700006 ER PT J AU Bae, HJ Sigman, J Park, SJ Heo, YH Boatner, LA Norton, DP AF Bae, HJ Sigman, J Park, SJ Heo, YH Boatner, LA Norton, DP TI Growth of semiconducting KTaO3 thin films SO SOLID-STATE ELECTRONICS LA English DT Article ID PULSED-LASER DEPOSITION; ELECTRICAL-PROPERTIES; CONDUCTION; MECHANISM; TITANATE; TARGETS AB In this study, the synthesis and semiconducting properties of cation and defect-doped KTaO3 films is reported. KTaO3 is an important material for optoelectronic and tunable microwave applications. It is an incipient ferroelectric with a cubic structure that becomes ferroelectric when doped with Nb. While numerous studies have investigated the thin-film growth of semiconducting perovskites, little is reported about semiconducting KTaO3 thin films. In this work, the films were grown on (1 0 0) MgO single crystal substrates using pulsed-laser deposition. Semiconducting behavior is achieved by inducing oxygen vacancies in the KTaO3 lattice via growth in a hydrogen atmosphere. The resistivity of semiconducting KTaO3:Ca films was as low as 10 Omega cm, and n-type semiconducting behavior was indicated. Hall mobility and carrier concentration were 0.27 cm(2)/N s and 3.2 x 10(18) cm(-3), respectively. Crystallinity and microstructure of the KTaO3:Ca films were examined using X-ray diffraction and field-emission scanning electron microscopy. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. EM dnort@mse.uf.edu RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 23 TC 6 Z9 7 U1 1 U2 12 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 EI 1879-2405 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2004 VL 48 IS 1 BP 51 EP 54 DI 10.1016/S0038-1101(03)00240-5 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 751DZ UT WOS:000187038700008 ER PT J AU Hasanuzzaman, M Islam, SK Tolbert, LM AF Hasanuzzaman, M Islam, SK Tolbert, LM TI Effects of temperature variation (300-600 K) in MOSFET modeling in 6H-silicon carbide SO SOLID-STATE ELECTRONICS LA English DT Article DE high temperature MOSFET; silicon carbide; temperature variation effect ID INTEGRATED-CIRCUITS; POWER DEVICES; 6H AB Silicon carbide (SiC) based devices perform very well in severe environments and show excellent device characteristics at very high temperatures and in high radiation environments. An analytical model for a lateral MOSFET that includes the effects of temperature variation in 6H-SiC poly-type has been developed. The effects of elevated ambient and substrate temperatures (300-600 K) on the electrical characteristics as well as the variation of large and small signal parameters of the lateral MOSFET have been studied. The model includes the effects of temperature on the threshold voltage, carrier mobility, the body leakage current, and the drain and source contact region resistances. The MOSFET output characteristics and parameter values have been compared with previously measured experimental data. A good agreement between the analytical model and the experimental data has been observed. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Natl Transport Res Ctr, Oak Ridge, TN 37831 USA. RP Hasanuzzaman, M (reprint author), Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. OI Tolbert, Leon/0000-0002-7285-609X NR 18 TC 21 Z9 25 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2004 VL 48 IS 1 BP 125 EP 132 DI 10.1016/S0038-1101(03)00293-4 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 751DZ UT WOS:000187038700019 ER PT J AU Kim, J Ren, F Baca, AG Chung, GY Pearton, SJ AF Kim, J Ren, F Baca, AG Chung, GY Pearton, SJ TI Thermal stability of WSiX Schottky contacts on n-type 4H-SiC SO SOLID-STATE ELECTRONICS LA English DT Article ID HIGH-TEMPERATURE; OHMIC CONTACTS; SILICON-CARBIDE; DIODE FORMATION; TUNGSTEN; GAN; 4H AB Sputter-deposited WSi0.45 rectifying contacts were characterized on n-type 4H-SiC as a function of annealing and measuremental temperature. The as-deposited contacts show evidence of recombination-dominated carrier transport and a high series resistance due to ion-induced damage occurring during the Ar plasma-assisted deposition. Annealing at 500 degreesC for 1 min produced a maximum barrier height of 1.15 eV and reduced the diode ideality factor. The contacts were degraded by annealing at >700 degreesC but showed reduced forward and reverse currents when measured at elevated temperature (300 degreesC) compared to the more common Ni rectifying contacts. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Sterling Semiconductor, Tampa, FL 33619 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. RI Kim, Jihyun/F-6940-2013 NR 23 TC 6 Z9 6 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JAN PY 2004 VL 48 IS 1 BP 175 EP 178 DI 10.1016/S0038-1101(03)00113-8 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 751DZ UT WOS:000187038700027 ER PT J AU Brosha, EL Mukundan, R Brown, DR Jia, QX Lujan, R Garzon, FH AF Brosha, EL Mukundan, R Brown, DR Jia, QX Lujan, R Garzon, FH TI Techniques for the thin film growth of La1-xSrxCrO3 for solid state ionic devices SO SOLID STATE IONICS LA English DT Article DE oxide thin films; lanthanum strontium chromate; mixed potential; sensors ID MIXED POTENTIAL SENSORS; OXIDE ELECTRODES; STABILIZED ZIRCONIA; AUTOMOTIVE APPLICATIONS; POTENTIOMETRIC SENSOR; CARBON-MONOXIDE; OXYGEN SENSORS; GAS SENSORS AB Thin films of LaCrO3 and La0.8Sr0.2CrO3 were prepared using RF magnetron sputtering, electron beam evaporation and pulsed laser deposition (PLD). The films were prepared from both oxide targets and from targets consisting of Cr metal and lanthanum and strontium fluorides. Subsequent anneal of the fluoride/metal composite films in humidified Ar produced an oxide film. Direct growth of the perovskite from oxide targets via sputtering was usually accompanied by second phases with Cr in valance states higher than 3+. Single-phase La-Sr-Cr-O films could not be prepared from a single oxide target electron beam evaporation. However, thick, stoichiometric films were prepared at 400degreesC using an electron bean/thermal evaporation dual source method but inconsistently. Single-phase lanthanum chromate films, based on the limited results obtained in this work, could not be prepared using PLD from either oxide or fluoride precursors under conditions similar to those used in the other techniques. However, films prepared by the intermediate fluoride process via off-axis RF magnetron sputtering process produced high quality thin films with density, microstructure and phase purity very similar to bulk La0.8Sr0.2CrO3, using a film growth temperature as low as ambient (T-sub < 100 degreesC). The deposition rate was typically low at approximately 1500 Angstrom/h. SEM analysis showed that the morphology of films produced via fluoride sputtering was nearly identical to bulk La0.8Sr0.2CrO3 prepared by sintering ceramic powders at 1650 degreesC in air and, based on previous work, should be suitable for mixed potential sensor applications. (C) 2004 Elsevier B.V All rights reserved. C1 Los Alamos Natl Lab, Elect & Electrochem Mat & Devices Grp, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Brosha, EL (reprint author), Los Alamos Natl Lab, Elect & Electrochem Mat & Devices Grp, POB 1663, Los Alamos, NM 87545 USA. EM brosha@lanl.gov RI Jia, Q. X./C-5194-2008 NR 32 TC 14 Z9 14 U1 2 U2 30 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD JAN PY 2004 VL 166 IS 3-4 BP 425 EP 440 DI 10.1016/j.ssi.2003.11.013 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 809BF UT WOS:000220611500022 ER PT S AU Bibeau, C Bayramian, AJ Beach, RJ Campbell, RW DeWald, A Davis, WH Dawson, JW Dimercurio, LE Ebbers, CA Freitas, BL Hill, MR Hood, KM Kanz, VK Menapace, JA Payne, SA Randles, MH Rankin, JE Schaffers, KI Stoltz, CJ Tassano, JB Telford, SJ Utterback, EJ AF Bibeau, C Bayramian, AJ Beach, RJ Campbell, RW DeWald, A Davis, WH Dawson, JW Dimercurio, LE Ebbers, CA Freitas, BL Hill, MR Hood, KM Kanz, VK Menapace, JA Payne, SA Randles, MH Rankin, JE Schaffers, KI Stoltz, CJ Tassano, JB Telford, SJ Utterback, EJ BE Scheps, R Hoffman, HJ TI Initial operation of the Mercury Laser - a gas cooled, 10 Hz, Yb : S-FAP system SO SOLID STATE LASERS XIII: TECHNOLOGY AND DEVICES SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Solid State Lasers XIII CY JAN 27-29, 2004 CL San Jose, CA SP SPIE AB We report initial operation of the Mercury laser with seven 4 x 6 cm S-FAP amplifier slabs pumped by four 80 kW diode arrays. The system produced up to 33.5 J single shot, 23.5 J at 5 Hz, and 10 J at 10 Hz for 20 minute runs at 1047 nm. During the initial campaign, more than 2.8 x 10(4) shots were accumulated on the system. The beam quality of the system was measured to be 2.8 x 6.3 times diffraction limited at 110 W of output, with 96% of the energy in a 5X diffraction limited spot. Static wavefront glass plates were used to correct for the low order distortions in the slabs due to fabrication and thermal loading. Scaling of crystal growth has begun with the first full size slab produced from large diameter growth. Using an energetics optimization code we find the beam aperture is scalable up to 20 x 30 cm and 4.2 kJ. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bibeau, C (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave,L-482, Livermore, CA 94550 USA. RI Hill, Michael/A-2525-2016 OI Hill, Michael/0000-0002-9168-211X NR 5 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5240-8 J9 P SOC PHOTO-OPT INS PY 2004 VL 5332 BP 244 EP 250 DI 10.1117/12.538414 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Materials Science; Optics; Physics GA BAQ78 UT WOS:000223223800028 ER PT S AU Bronold, F Saxena, A Smith, DL AF Bronold, F Saxena, A Smith, DL BE Ehrenreich, H Spaepen, F TI Electron spin dynamics in semiconductors SO SOLID STATE PHYSICS, VOL 58 SE Solid State Physics LA English DT Review ID GAAS QUANTUM-WELLS; N-TYPE GAAS; III-V; GIANT MAGNETORESISTANCE; 2-DIMENSIONAL ELECTRONS; MAGNETIC SEMICONDUCTORS; CONDUCTION ELECTRONS; RELAXATION DYNAMICS; SPINTRONIC DEVICE; GALLIUM-ARSENIDE C1 Ernst Moritz Arndt Univ Greifswald, Inst Phys, D-17487 Greifswald, Germany. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ernst Moritz Arndt Univ Greifswald, Inst Phys, D-17487 Greifswald, Germany. NR 153 TC 6 Z9 6 U1 5 U2 11 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0081-1947 BN 0-12-607758-4 J9 SOLID STATE PHYS JI Solid State Phys. PY 2004 VL 58 BP 73 EP 166 DI 10.1016/S0081-1947(04)80010-9 PG 94 WC Physics, Condensed Matter SC Physics GA BAQ33 UT WOS:000223200500002 ER PT B AU Sabau, AS Porter, WD Frankel, JI AF Sabau, AS Porter, WD Frankel, JI BE Chu, MG Granger, DA Han, QY TI Conduction and radiation parameters for analytical models of differential scanning calorimetry instruments SO SOLIDIFICATION OF ALUMINUM ALLOYS LA English DT Proceedings Paper CT Symposium on Solidification of Aluminum Alloys held at the TMS 2004 Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP TMS, Mat Proc & Mfg Div, Solidificat Comm DE heat flux; differential scanning calorimeter; temperature lag; analytical model ID HEAT-FLUX DSC; ALLOYS AB Differential Scanning Calorimetry (DSC) measurements are routinely used to determine enthalpies of phase change, phase transition temperatures, glass transition temperatures, and heat capacities. DSC data has also been used to estimate the fractional latent heat release during phase changes. To date, DSC measurements are plagued by temperature lags due to the fact that the temperatures are measured using thermocouples that are placed at a different location than that of the sample and reference materials. In this study, the temperature lags, which are inherent to the measurement process, are estimated through a computational analysis of the raw DSC data. An analytical model is presented that accounts for different heat transfer mechanisms among instrument components. Through a direct analysis, it is shown that the proposed analytical model can accurately describe the experimental data. The direct analysis presented is to be complemented by inverse process analysis in order to determine more accurate values for the model parameters. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Sabau, AS (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Sabau, Adrian/0000-0003-3088-6474 NR 8 TC 1 Z9 1 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-569-7 PY 2004 BP 19 EP 28 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY79F UT WOS:000189464200002 ER PT B AU Han, Q Hassan, MI Viswanathan, S Saito, K Das, SK AF Han, Q Hassan, MI Viswanathan, S Saito, K Das, SK BE Chu, MG Granger, DA Han, QY TI An experimental method for determining mechanical properties in the non-equilibrium mushy zones of alloys SO SOLIDIFICATION OF ALUMINUM ALLOYS LA English DT Proceedings Paper CT Symposium on Solidification of Aluminum Alloys held at the TMS 2004 Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP TMS, Mat Proc & Mfg Div, Solidificat Comm DE hot tearing; mechanical properties; mushy zone; aluminum alloys ID TENSILE-STRENGTH; ALUMINUM-ALLOYS; TEMPERATURE; BEHAVIOR; DEFORMATION; SOLIDIFICATION; FRACTURE; STEELS AB The mushy zone of an alloy is in non-equilibrium during solidification. The mechanical properties of alloys in this non-equilibrium mushy zone, especially at small liquid fractions, are closely related to the formation of hot tears during the solidification of castings. It is difficult to measure the mechanical properties in the non-equilibrium mushy zones of alloys at a small liquid fraction as the liquid fraction decreases rapidly during heating and during the isothermal hold needed to measure mechanical properties, due to back diffusion in the solid. This paper describes a new experimental method for determining mechanical properties in the non-equilibrium mushy zones of alloys. Initial results indicate that the method is better than traditional methods in capturing the brittle nature of alloys at temperatures close to the non-equilibrium solidus temperature. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Han, Q (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-569-7 PY 2004 BP 211 EP 220 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY79F UT WOS:000189464200020 ER PT B AU Vitek, JM Babu, SS Park, JW David, SA AF Vitek, JM Babu, SS Park, JW David, SA BE Rappaz, M Beckermann, C Trivedi, R TI Stray grain formation in nickel-base superalloy single-crystal welds SO SOLIDIFICATION PROCESSES AND MICROSTRUCTURES: A SYMPOSIUM IN HONOR OF WILFRIED KURZ LA English DT Proceedings Paper CT Symposium on Solidification Processes and Microstructures in Honor of Wilfried Kurz held at the TMS Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP Minerals , Met & Mat Soc, Solidificat Comm, Mat Proc & Mfg Div DE single crystals; dendritic growth; stray grains; nickel-based superalloys ID ELECTRON-BEAM WELDS; MICROSTRUCTURAL DEVELOPMENT; SOLIDIFICATION AB A single-crystal nickel-based superalloy (alloy Rene N5) was welded using laser and electron beam processes. The resultant microstructure was examined by optical microscopy. It was found that extensive stray grain formation took place, and furthermore, the stray grain formation was not symmetrical with respect to the weld centerline. The results were interpreted with the use of the theories of Kurz and co-workers on dendrite tip growth and constitutional supercooling ahead of the advancing dendrite solidification front. It was found that the theories explain the observations quite well, and provide the basis for optimizing the weld conditions in the future so as to yield stray-grain free welds in single crystals. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Vitek, JM (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 13 TC 1 Z9 1 U1 0 U2 3 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-572-7 PY 2004 BP 61 EP 66 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY80J UT WOS:000189466900008 ER PT B AU Liu, S Suk, MJ Fabietti, L Trivedi, R AF Liu, S Suk, MJ Fabietti, L Trivedi, R BE Rappaz, M Beckermann, C Trivedi, R TI The effect of dimensionality on microstructures in directionally solidified SCN-Salol alloys SO SOLIDIFICATION PROCESSES AND MICROSTRUCTURES: A SYMPOSIUM IN HONOR OF WILFRIED KURZ LA English DT Proceedings Paper CT Symposium on Solidification Processes and Microstructures in Honor of Wilfried Kurz held at the TMS Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP Minerals , Met & Mat Soc, Solidificat Comm, Mat Proc & Mfg Div DE directional solidification; SCN-Salol system; interface stability; dimensionality effect; growth morphology ID GROWTH AB Directional solidification experiments have been conducted in SCN-0.7wt%Salol alloy with an emphasis on morphological evolution and pattern formation under different geometrical conditions. Two sample configurations were used in the study: a traditional thin-sandwiched glass cell and a capillary tube. For the former, cells of four different thicknesses were used: 12, 50, 100 and 200 mum.With fixed alloy composition, temperature gradient and growth velocity, the growth morphology was found to depend significantly on the sample thickness. For example, in a 12 mum thick sample, only dendritic structures formed even at very low velocity where a planar front stability is predicted for a bulk sample. For capillary samples, two diameters, 75 and 100 mum, were used and the growth patterns in these capillaries will be compared with the morphology in a 2D thin film sample. C1 Iowa State Univ Sci & Technol, Ames Lab, Mat & Engn Phys Program, Ames, IA 50011 USA. RP Liu, S (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Mat & Engn Phys Program, Ames, IA 50011 USA. NR 20 TC 4 Z9 4 U1 0 U2 4 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-572-7 PY 2004 BP 211 EP 218 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY80J UT WOS:000189466900026 ER PT B AU Napolitano, RE Jung, C Meco, H AF Napolitano, RE Jung, C Meco, H BE Rappaz, M Beckermann, C Trivedi, R TI Growth mechanisms in low-velocity Al-Si eutectics SO SOLIDIFICATION PROCESSES AND MICROSTRUCTURES: A SYMPOSIUM IN HONOR OF WILFRIED KURZ LA English DT Proceedings Paper CT Symposium on Solidification Processes and Microstructures in Honor of Wilfried Kurz held at the TMS Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP Minerals , Met & Mat Soc, Solidificat Comm, Mat Proc & Mfg Div DE eutectic solidification; faceted growth; angular morphology ID ALLOYS; SILICON AB Morphological selection and texture evolution is investigated in aluminum-silicon eutectics, grown at low velocity. It is found that rapid lateral growth of the angular star-shaped structures results in complete <001> texturing within the first 40 Him of growth. The details of the resulting growth morphologies are discussed. C1 Iowa State Univ, US DOE, Ames Lab, Dept Mat Sci & Engn,Mat & Engn Phys Program, Ames, IA 50011 USA. RP Napolitano, RE (reprint author), Iowa State Univ, US DOE, Ames Lab, Dept Mat Sci & Engn,Mat & Engn Phys Program, Ames, IA 50011 USA. NR 9 TC 0 Z9 0 U1 1 U2 4 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-572-7 PY 2004 BP 245 EP 250 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY80J UT WOS:000189466900031 ER PT B AU Liu, S Lee, JH Enlow, D Trivedi, R AF Liu, S Lee, JH Enlow, D Trivedi, R BE Rappaz, M Beckermann, C Trivedi, R TI Lamellar/rod transition in Al-Cu alloys SO SOLIDIFICATION PROCESSES AND MICROSTRUCTURES: A SYMPOSIUM IN HONOR OF WILFRIED KURZ LA English DT Proceedings Paper CT Symposium on Solidification Processes and Microstructures in Honor of Wilfried Kurz held at the TMS Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP Minerals , Met & Mat Soc, Solidificat Comm, Mat Proc & Mfg Div DE eutectic solidification; lamellar/rod transition; convection; growth dynamics ID EUTECTIC GROWTH; SYSTEMS; SN; MICROSTRUCTURE; SELECTION; DENDRITE; PB AB A binary eutectic generally forms a lamellar or a rod eutectic structure, and the transition between them largely depends on the volume fraction of the minor constituent in the eutectic structure. Through detailed experimental studies in the Al-Cu system, we have examined the regimes of the stability of these two morphologies and characterized the dynamics of the transition. We have found that the transition is not sharp and the two morphologies co-exist over a range of volume fractions. Theoretical ideas have been presented for this co-existence regime and a modified criterion for the lamellar/rod transition is proposed. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Liu, S (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 23 TC 4 Z9 4 U1 2 U2 5 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-572-7 PY 2004 BP 257 EP 262 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY80J UT WOS:000189466900033 ER PT B AU Trivedi, R Liu, S Echebarria, B Karma, A AF Trivedi, R Liu, S Echebarria, B Karma, A BE Rappaz, M Beckermann, C Trivedi, R TI Microstructural scaling relationships in cellular patterns SO SOLIDIFICATION PROCESSES AND MICROSTRUCTURES: A SYMPOSIUM IN HONOR OF WILFRIED KURZ LA English DT Proceedings Paper CT Symposium on Solidification Processes and Microstructures in Honor of Wilfried Kurz held at the TMS Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP Minerals , Met & Mat Soc, Solidificat Comm, Mat Proc & Mfg Div DE cellular growth; scaling laws; phase-field; transparent alloys ID HELE-SHAW CELL; DIRECTIONAL SOLIDIFICATION; 3 DIMENSIONS; DENDRITES; STABILITY; GROWTH; ARRAY AB In a cellular array, a strong coupling of solute field exists between neighboring cells so that a significant scatter in primary spacing and in cell shape is present in a given array. Through experimental studies and phase-field modeling, we have found that the apparent disorder in cells follows some definite scaling laws. When only cells are present in an array, all apparently differing cell shapes collapse (within optical resolution) onto a single shape when they are scaled with the local spacing. This shape interpolates between two known limits of this problem: the Scheil equation and the 2-d Saffman-Taylor (ST) equation which describes the Laplacian limit of directional growth. The former predicts the asymptotic shape of the interface far from the tip while the latter is found here to predict reasonably well the cell tip of experimental and numerical cell shapes. The predicted tip undercooling based on the ST shape is also in good agreement with the 2-d phase-field results. In addition, experimental results are presented showing that the cells in the presence of intercellular eutectic follow the solution of the 3-d ST problem. Finally, the phase-field results are strikingly different for 2-d shapes and 3-d axisymmetric shapes: steady-state cells exist in 2-d over a very wide range of spacing, but they only exist in 3-d up to a maximum spacing that is significantly smaller than the lower limit of the experimentally observed range of spacing. The existence of this band gap in 3-d cell solutions is consistent with previous numerical solutions of the 3-d ST problem. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Trivedi, R (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Echebarria, Blas/K-5247-2014 OI Echebarria, Blas/0000-0003-0503-1781 NR 22 TC 4 Z9 4 U1 2 U2 3 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-572-7 PY 2004 BP 307 EP 318 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY80J UT WOS:000189466900039 ER PT B AU Babu, SS Vitek, JM Elmer, JW Palmer, TA David, SA AF Babu, SS Vitek, JM Elmer, JW Palmer, TA David, SA BE Rappaz, M Beckermann, C Trivedi, R TI Nonequilibrium phase selection during weld solidification of Fe-C-Mn-Al steels SO SOLIDIFICATION PROCESSES AND MICROSTRUCTURES: A SYMPOSIUM IN HONOR OF WILFRIED KURZ LA English DT Proceedings Paper CT Symposium on Solidification Processes and Microstructures in Honor of Wilfried Kurz held at the TMS Annual Meeting CY MAR 14-18, 2004 CL Charlotte, NC SP Minerals , Met & Mat Soc, Solidificat Comm, Mat Proc & Mfg Div DE steel; weld; solidification; phase selection; time-resolved X-ray diffraction; modeling; synchrotron ID X-RAY-DIFFRACTION; CORED ARC WELDS; MICROSTRUCTURE SELECTION; RAPID SOLIDIFICATION; GAMMA-TRANSITION; DENDRITE-GROWTH; LASER TREATMENT; NI ALLOYS; DELTA AB The phase selection phenomenon as a function of interface growth velocity was investigated in an Fe-C-Al-Mn self-shielded flux cored arc weld metal deposit. In this steel, the primary solidification occurs by delta-ferrite formation under normal weld cooling conditions. With an increase in liquid-solid interface velocity, a transition to nonequilibrium austenite solidification is observed. The above phase selection phenomenon was monitored in-situ using a time-resolved X-ray diffraction technique employing Synchrotron radiation. Using the theoretical treatment of dendritic solidification and phase selection maps advanced by Kurz and his co-workers, the microstructure evolution at high weld solidification rates was evaluated. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Babu, SS (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Babu, Sudarsanam/D-1694-2010 OI Babu, Sudarsanam/0000-0002-3531-2579 NR 17 TC 0 Z9 0 U1 0 U2 4 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-572-7 PY 2004 BP 339 EP 344 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY80J UT WOS:000189466900043 ER PT J AU Stepinski, DC McAlister, DR Zalupski, PR Chiarizia, R Herlinger, AW AF Stepinski, DC McAlister, DR Zalupski, PR Chiarizia, R Herlinger, AW TI An investigation of ester group steric effects on metal ion extraction by symmetrically substituted methylenediphosphonic acids SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE diphosphonic acids; steric effects; ester substituent; metal ion extraction ID P,P'-DI(2-ETHYLHEXYL) METHANEDIPHOSPHONIC ACID; METHANE DIPHOSPHONIC ACIDS; SOLVENT-EXTRACTION; CARBOXYLIC-ACIDS; COMPLEXES; THORIUM(IV); AGGREGATION; FACILE AB Symmetrically substituted partial alkyl-esters of methylenediphosphonic acid are powerful metal ion extractants for actinides in all oxidation states. A preliminary study of calcium and americium(III) extraction by the n-octyl and 2-ethylhexyl di-substituted esters of methylenediphosphonic acid revealed the distribution ratios and the nitric acid dependency behaviors for the two extractants to be very similar, with the extraction efficiency for the n-octyl ester somewhat higher than for the 2-ethylhexyl derivative. Since the basicity of the phosphoryl groups in the two extractants should be essentially the same, the differences in the solvent extraction efficiency of these two C-8-alkyl-substituted ligands could arise from differences in the steric requirements of the ester groups. Ester group steric effects on metal ion extraction for a series of symmetrically alkyl-substituted partial esters and identically substituted tetra-esters of methylenediphosphonic acid were investigated to gain insight into these differences. The symmetrical tetra-esters were included in this study to avoid potential complications from the strong hydrogen bonding and aggregation effects associated with the partial esters. Specifically, strontium and americium(Ill) extraction by n-hexyl, 2,4,4-trimethylpentyl and cyclohexyl di-esters of methylenediphosphonic acid, and americium(Ill) extraction by identically substituted n-hexyl, 2,4,4-trimethylpentyl, 3-(trimethylsilyl)propyl and 2-ethylhexyl tetra-esters were measured. This data demonstrates the influence of ester group steric requirements on the solvent extraction efficiency of alkyl-substituted methylenediphosphonic acids. C1 Loyola Univ, Dept Chem, Chicago, IL 60626 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Herlinger, AW (reprint author), Loyola Univ, Dept Chem, 6525 N Sheridan Rd, Chicago, IL 60626 USA. EM aherlin@luc.edu NR 23 TC 3 Z9 3 U1 0 U2 2 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 1 BP 89 EP 103 DI 10.1081/SEI-120028004 PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA 800DK UT WOS:000220008900006 ER PT J AU Chiarizia, R Jensen, MP Borkowski, M Thiyagarajan, P Littrell, KC AF Chiarizia, R Jensen, MP Borkowski, M Thiyagarajan, P Littrell, KC TI Interpretation of third phase formation in the Th(IV)-HNO3, TBP-n-octane system with Baxter's "sticky spheres" model SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE Baxter model; small-angle neutron scattering; tri-n-butylphosphate-n-octane; HNO3-Th(NO3)(4); third phase formation ID ANGLE NEUTRON-SCATTERING; 3RD PHASE-FORMATION; METHANEDIPHOSPHONIC ACID; 3RD-PHASE FORMATION; SURFACE-ADHESION; DODECANE SYSTEM; METAL-CATIONS; HARD-SPHERES; NITRIC-ACID; FT-IR AB Small-angle neutron scattering (SANS) data for the tri-n-butylphosphate (TBP)-n-octane, HNO3-Th(NO3)(4) solvent extraction system, obtained under a variety of experimental conditions, have been interpreted using two different models. The particle growth model led to unrealistic results. The Baxter model for hard-spheres with surface adhesion, on the other hand, was more successful. According to this model, the increase in scattering intensity in the low Q range observed when increasing amounts of Th(NO3)(4) are extracted into the organic phase, has been interpreted as arising from interactions between small reverse micelles containing three TBP molecules. Upon extraction of Th(NO3)(4), the micelles interact through attractive forces between their polar cores with a potential energy of up to about 2 k(B)T. The intermicellar attraction, under suitable conditions, leads to third phase formation. Upon phase splitting, most of the solutes of the original organic phase separate in a continuous phase containing interspersed layers of n-octane. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, IPNS Div, Argonne, IL 60439 USA. RP Chiarizia, R (reprint author), Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. EM chiarizia@anl.gov RI Jensen, Mark/G-9131-2012; Littrell, Kenneth/D-2106-2013 OI Jensen, Mark/0000-0003-4494-6693; Littrell, Kenneth/0000-0003-2308-8618 NR 31 TC 34 Z9 35 U1 2 U2 6 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 3 BP 325 EP 351 DI 10.1081/SEI-120030394 PG 27 WC Chemistry, Multidisciplinary SC Chemistry GA 827XY UT WOS:000221938200001 ER PT J AU Yaita, T Herlinger, AW Thiyagarajan, P Jensen, MP AF Yaita, T Herlinger, AW Thiyagarajan, P Jensen, MP TI Influence of extractant aggregation on the extraction of trivalent f-element cations by a tetraalkyldiglycolamide SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE TODGA; small-angle neutron scattering; vapor pressure osomometry; lanthanide; actinide ID NITRIC-ACID; SOLVENT-EXTRACTION; N-DODECANE; COMPLEXES; SYSTEM; SEPARATIONS; ACTINIDES; BEHAVIOR; IONS AB The influence of nitric acid extraction on the aggregation state of 0.10M N,N,N',N'-tetra-n-octyl-3-oxapentane-1,5-diamide (TODGA) in n-octane or n-heptane was studied by small-angle neutron scattering (SANS) and vapor pressure osmometry (VPO). When the equilibrium concentration of nitric acid in the aqueous phase is less than 0.7 M, TODGA exists as a mixture of monomers and dimers. As the aqueous phase acidity is increased, the extractant molecules form higher aggregates containing up to an average of seven molecules of TODGA. The formation of the larger TODGA aggregates takes place over the same range of aqueous acidities where the extraction of trivalent f-element cations displays a hyperstoichiometric sixth power nitric acid dependence. This suggests that acid-driven aggregation of TODGA is responsible for the unusual acid and extractant dependencies observed for the extraction of trivalent metal nitrates with this ligand. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. Loyola Univ, Dept Chem, Chicago, IL 60611 USA. Japan Atom Energy Res Inst, Dept Mat Sci, Tokai, Ibaraki 31911, Japan. RP Jensen, MP (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM mjensen@anl.gov RI Jensen, Mark/G-9131-2012 OI Jensen, Mark/0000-0003-4494-6693 NR 31 TC 59 Z9 59 U1 3 U2 17 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 4 BP 553 EP 571 DI 10.1081/SEI-120039640 PG 19 WC Chemistry, Multidisciplinary SC Chemistry GA 842QL UT WOS:000223019000002 ER PT J AU Engle, NL Bonnesen, PV Tomkins, BA Haverlock, TJ Moyer, BA AF Engle, NL Bonnesen, PV Tomkins, BA Haverlock, TJ Moyer, BA TI Synthesis and properties of calix[4]arene-bis[4-(2-ethylhexyl)benzo-crown-6], a cesium extractant with improved solubility SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE calixcrown; macrocycle; solubility; third phase; cesium extraction; CSSX; BOBCalixC6; BEHBCalixC6 ID DODECAMOLYBDOPHOSPHATE ANION; SOLVENT-EXTRACTION; TANK WASTE; REMOVAL AB The new cesium-selective macrocycle calix[4]arene-bis[4-(2-ethylhexyl) benzo-crown-6] ("BEHBCalixC6") has been found to have improved solubility in a modified alkane diluent over calix[4]arene-bis(4-tert-octylbenzo-crown-6) ("BOBCalixC6"). The synthesis of this new calixcrown extractant, together with its solubility and extraction properties, is described in this report. The solubility, cesium extraction, and potassium loading behavior are compared with those of BOBCalixC6, the macrocycle currently employed in the caustic-side solvent extraction (CSSX) process for extracting cesium from alkaline nitrate solutions such as high-level nuclear waste. Replacement of the tert-octyl alkyl chains on the benzo-crown portion of the calixcrown by 2-ethylhexyl chains improves the equilibrium solubility of the free calixcrown in aliphatic diluents while not affecting the cesium extraction strength. Equilibrium concentrations of BEHBCaIixC6 in Isopar L diluent modified with 0.5 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) over the course of 41 weeks of gentle agitation at 25degreesC maintained the initial concentration of 57 +/- 2 mM, with no evidence of precipitation or third-phase formation. In contrast, 57 +/- 2 mM solutions of BOBCalixC6 prepared using sonication were not stable, with precipitation occurring to afford an equilibrium concentration of only 6.7 +/- 0.2 mM after 41 weeks. Third-phase tests showed that BEHBCalixC6 resists third-phase formation as well as, or better than, BOBCalixC6. With increasing potassium loading from an alkaline sodium nitrate solution, both calixcrowns at 20 mM in modified Isopar L exhibited comparable onset of third-phase formation, gauging by the decreasing mass balance in cesium extraction from the same solutions. However, the BEHBCalixC6 solvent exhibited no visible indications of third-phase formation until the aqueous potassium concentration reached 0.75 M, whereas the BOBCalixC6 suffered visible third-phase formation when the aqueous potassium nitrate concentration reached 0.25 M. Calixcrowns with higher solubility in alkane diluents may find application in cesium extraction from waste matrices containing moderate (greater than or equal to0.2 M) quantities of potassium, such as that stored at the US Department of Energy's Hanford Site, where higher concentrations of the calixcrown extractant may be required to obtain practical cesium distribution coefficients for process flowsheets. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Bonnesen, PV (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. EM bonnesenpv@ornl.gov RI Solominow, Sonia/A-4021-2008; Bonnesen, Peter/A-1889-2016; Moyer, Bruce/L-2744-2016; OI Bonnesen, Peter/0000-0002-1397-8281; Moyer, Bruce/0000-0001-7484-6277; Tomkins, Bruce/0000-0001-8520-1415; Engle, Nancy/0000-0003-0290-7987 NR 19 TC 21 Z9 21 U1 3 U2 10 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 4 BP 611 EP 636 DI 10.1081/SEI-120039639 PG 26 WC Chemistry, Multidisciplinary SC Chemistry GA 842QL UT WOS:000223019000005 ER PT J AU Bazelaire, E Gorbunova, MG Bonnesen, PV Moyer, BA Delmau, LH AF Bazelaire, E Gorbunova, MG Bonnesen, PV Moyer, BA Delmau, LH TI PH-Switchable cesium nitrate extraction with calix[4]arene mono and bis(benzo-crown-6) ethers bearing amino functionalities SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE cesium extraction; solvent extraction; aminocalixarene; calix[4]arene-crown-6 ID 1,3-ALTERNATE; 1,2-DICHLOROETHANE; WASTE AB Results obtained in this work show that four calix[4]arene mono and bis(benzo-crown-6) ethers functionalized with primary amine groups feature markedly enhanced cesium stripping under acidic conditions compared with nonfunctionalized analogs. The four amine-derivatized calixarenes were surveyed in nitrobenzene diluent at 25degreesC, demonstrating the effect under controlled conditions, where it was seen that the amino functionalization entailed at most a mild sacrifice of cesium extraction strength or selectivity. Limited solubility of the protonated forms of C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. RP Delmau, LH (reprint author), Oak Ridge Natl Lab, Div Chem Sci, POB 2008, Oak Ridge, TN 37831 USA. EM delmaulh@ornl.gov RI Solominow, Sonia/A-4021-2008; Moyer, Bruce/L-2744-2016 OI Moyer, Bruce/0000-0001-7484-6277 NR 13 TC 13 Z9 14 U1 0 U2 5 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 4 BP 637 EP 661 DI 10.1081/SEI-120039637 PG 25 WC Chemistry, Multidisciplinary SC Chemistry GA 842QL UT WOS:000223019000006 ER PT J AU Hassan, NM Adu-Wusu, K Nash, CA Marra, JC AF Hassan, NM Adu-Wusu, K Nash, CA Marra, JC TI Multiple ion exchange column tests for technetium removal from Hanford site Tank 241-AW-101 with Superlig (R) 639 resin SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE Hanford waste tank; Superlig((R)) 639 resin; technetium; decontamination ID SORPTION BEHAVIOR; PERTECHNETATE; EXTRACTION; CHROMATOGRAPHY; RESIN; SIMULANT; WASTES; ABEC AB Five cycles of loading, elution, and regeneration were performed to remove technetium in the form of pertechnetate from a Hanford waste sample retrieved from Tank 241-AW-101 using SuperLig(R) 639 resin. The waste sample was diluted to 4.95 M Na+ and then processed to remove Cs-137 through dual ion exchange columns, each containing 15 mL of SuperLig(R) 644. To remove technetium, the cesium decontaminated solution was processed downwards through two ion exchange columns, each containing 12 mL of the SuperLig(R) 639 resin. The columns, designated as lead and lag, each had an inside diameter of 1.45 cm and a height of 30 cm. The columns were loaded in series, but were eluted and then regenerated separately. The average technetium loading for the cycles was 250 BV (bed volume) at 10% breakthrough. There was no significant difference in the loading performances among the five cycles. The percent removal of technetium in the pertechnetate form (TcO4-) was >99.94% and the average de-contamination factor (DF) was similar to 1.7 x 10(3). Approximately 99% of the TcO4- loaded on the resin was eluted with < 15 BV of deionized water at 65degreesC. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Hassan, NM (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. EM neguib.hassan@srs.gov NR 20 TC 1 Z9 1 U1 1 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 4 BP 663 EP 680 DI 10.1081/SEI-120039636 PG 18 WC Chemistry, Multidisciplinary SC Chemistry GA 842QL UT WOS:000223019000007 ER PT J AU Lumetta, GJ Wester, DW McNamara, BK Hubler, TL Latesky, SL Martyr, CC Richards, KN AF Lumetta, GJ Wester, DW McNamara, BK Hubler, TL Latesky, SL Martyr, CC Richards, KN TI A new extraction chromatography resin containing Klaui ligands for application in actinide separations SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE americium; plutonium; Klaui ligand ID RAY CRYSTAL-STRUCTURE; SANDWICH COMPOUNDS; COMPLEXES; TRINUCLEAR; REACTIVITY; NMR AB An extraction chromatography resin containing the anionic ligand (eta(5)-pentamethylcyclopentadienyl)tris-(diethylphosphito-P)cobalt(III), Cp*Co[P(O)(OEt)(2)](3)(-) (1Et) has been prepared. The resin consists of 1 wt% 1Et on Amberlite(R) XAD-7. This resin strongly sorbs AM(3+) and Pu4+. The sorption of these ions decreases with increasing nitric acid concentration, but this effect is more pronounced for Am3+. This allows for convenient separation of Am3+ from Pu4+ by simple adjustments in the HNO3 concentration. The tripodal geometry of 1Et disfavors the complexation of UO22+ so sorption of U(VI) by the 1Et-containing resin is weak. An analogous resin containing Cp*Co[P(O)(OPr)(2)](3)(-) (1Pr) shows similar Pu4+ sorption behavior. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Univ Virgin Isl, Div Sci & Math, St Thomas, VI USA. RP Lumetta, GJ (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. EM gregg.lumetta@pnl.gov NR 21 TC 4 Z9 4 U1 1 U2 1 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 6 BP 947 EP 960 DI 10.1081/SEI-200037442 PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 872YK UT WOS:000225245200004 ER PT J AU Hassan, NM Adu-Wusu, K Nash, CA Marra, JC AF Hassan, NM Adu-Wusu, K Nash, CA Marra, JC TI Multiple ion exchange column tests for cesium (CS+) removal from Hanford Site tank 241-AW-101 with SuperLig (R) 644 resin SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE ion exchange column; cesium; Hanford waste ID SILICA-GEL; METAL-IONS; RESIN; WASTE; ABSORPTION; CATIONS AB Six cycles of loading, elution, and regeneration were performed to remove cesium (Cs+) from a Hanford Site tank waste sample using SuperLig(R) 644 resin. The sample, which was retrieved from Tank 241-AW-101, was diluted to 5.09M Na+ and processed through dual ion exchange columns to remove Cs-137. Each column had an inside diameter of 1.45cm and a height of 30cm; and contained 15mL of wet resin in the sodium form. The columns, designated as primary (lead) and polishing (lag), were connected in series during loading, but they were separated during elution and regeneration. The cesium loading on the primary column during the six cycles ranged from 160 to 225 bed volumes (BV) at <50% breakthrough. A gradual decline of the resin loading performances was observed as a function of number of loading cycles. For all cycles, the percent removal of cesium (Cs-137) was greater than 99.99% and the decontamination factors (DFs) achieved were higher than 1.0 x 10(4). Elution of the resin with 0.5 M nitric acid at 25 +/- 2degreesC was effective. Approximately 99% of the Cs-137 bound on the resin was eluted with less than 15 BV of the eluent (0.5M nitric acid). The cumulative dose absorbed by the resin in the primary column was 1.99 x 10(7) rad with a 20% loss of ion exchange capacity was at 50% breakthrough after completing six loading cycles. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Hassan, NM (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. EM neguib.hassan@srs.gov NR 29 TC 9 Z9 9 U1 2 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 6 BP 979 EP 996 DI 10.1081/SEI-200037459 PG 18 WC Chemistry, Multidisciplinary SC Chemistry GA 872YK UT WOS:000225245200006 ER PT J AU Veeck, AC White, DJ Whisenhunt, DW Xu, JD Gorden, AEV Romanovski, V Hoffman, DC Raymond, KN AF Veeck, AC White, DJ Whisenhunt, DW Xu, JD Gorden, AEV Romanovski, V Hoffman, DC Raymond, KN TI Hydroxypyridinone extraction agents for Pu(IV) SO SOLVENT EXTRACTION AND ION EXCHANGE LA English DT Article DE hydroxypyridinone; decontamination factor; dicyclohexylurea; dimethylaminopyridine ID SEQUESTERING AGENTS; ACTINIDES; LIGANDS; PLUTONIUM(IV); MIMOSINE; REMOVAL AB Twelve different extraction agents, based on the hydroxypyridinone (HOPO) chelating moieties 3,2-HOPO, 3,4-HOPO, and 1,2-HOPO, have been synthesized and characterized for their ability to remove Pu(IV) from nitric acid Solutions. Most of these, in particular those based on 1,2-HOPO, displayed very rapid extraction kinetics and extracted Pu(IV) with large distribution ratios. They were also highly effective in removing Pu(IV) front solutions containing high concentrations of Fe(III) or ethylenediaminetetraacetic acid (EDTA). Stripping the bound Pu(IV) from the chelate complex proved challenging, as only similar to40% was removed even with concentrated (15.8 M) nitric acid. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Glenn T Seaborg Inst Transactinium Sci, Lawrence Livermore Natl Lab, Livermore, CA USA. RP Raymond, KN (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM raymond@socrates.berkeley.edu RI Gorden, Anne/D-2477-2011 OI Gorden, Anne/0000-0001-6623-9880 NR 27 TC 12 Z9 12 U1 1 U2 5 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0736-6299 J9 SOLVENT EXTR ION EXC JI Solvent Extr. Ion Exch. PY 2004 VL 22 IS 6 BP 1037 EP 1068 DI 10.1081/SEI-200037773 PG 32 WC Chemistry, Multidisciplinary SC Chemistry GA 872YK UT WOS:000225245200009 ER PT J AU Willson, JD Dorcas, ME AF Willson, JD Dorcas, ME TI Aspects of the ecology of small fossorial snakes in the Western piedmont of North Carolina SO SOUTHEASTERN NATURALIST LA English DT Article ID STORERIA-OCCIPITOMACULATA AB In many areas, small fossorial snakes are among the most abundant vertebrates present; yet, the ecology of these species remains poorly understood. Between 1999 and 2002 we collected 2 10 small fossorial snakes representing five species in a small area of northern Mecklenburg and Southern Iredell Counties, North Carolina. The eastern worm snake (Carphophis amoenus; n = 116) was the most frequently captured species in this region, with fewer numbers of ringneck snakes (Diadophis punctants; n = 44), brown snakes (Storeria dekayi; n = 24), redbellied snakes (S. occipitomaculata; n = 20), and smooth earth snakes (Virginia valeriae; n = 6). The three most abundant species exhibited significant sexual dimorphism, with females being larger and having shorter relative tail lengths than males. Carphophis amoenus were more abundant in dry upland forest than D. punctatus, which were most prevalent in moist, lowland forest. Snake activity was weakly correlated with environmental conditions. A peak in activity of male C. amoenus, D. punctatus, and S. occipitomaculata during September suggests fall breeding seasons for these species. C1 Davidson Coll, Dept Biol, Davidson, NC 28035 USA. RP Willson, JD (reprint author), Savannah River Ecol Lab, Aiken, SC 29802 USA. EM willson@srel.edu NR 32 TC 38 Z9 43 U1 5 U2 19 PU HUMBOLDT FIELD RESEARCH INST PI STEUBEN PA PO BOX 9, STEUBEN, ME 04680-0009 USA SN 1528-7092 J9 SOUTHEAST NAT JI Southeast. Nat. PY 2004 VL 3 IS 1 BP 1 EP 12 DI 10.1656/1528-7092(2004)003[0001:AOTEOS]2.0.CO;2 PG 12 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 809RQ UT WOS:000220654200001 ER PT J AU Glaudas, X AF Glaudas, X TI Do cottonmouths (Agkistrodon piscivorus) habituate to human confrontations? SO SOUTHEASTERN NATURALIST LA English DT Article ID SNAKE THAMNOPHIS-RADIX; DEFENSIVE BEHAVIOR; GARTER SNAKE; ANTIPREDATOR RESPONSES; PRAIRIE RATTLESNAKES; PSEUDONAJA-TEXTILIS; BODY-TEMPERATURE; VIRIDIS; SIRTALIS; ELAPIDAE AB The defensive behavior of snakes towards humans has been well documented. Ironically, many of these early studies focused on harmless colubrid species. Knowledge of venomous snake defensive behavior is limited, and further research is necessary to understand how pitvipers react to human confrontations. I performed laboratory tests daily over a period of five days to investigate whether cottonmouths would habituate to handling. Eleven days after the last habituation test, snakes were tested again to see if cottonmouths show a recovery response. Cottonmouths exhibited a significant change in defensive behavior between Day 1 and Day 5 of the experiment. However, they did not significantly revert to their original behavior 11 days later. C1 Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Glaudas, X (reprint author), Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. EM xavier@srel.edu OI Glaudas, Xavier/0000-0002-1333-7791 NR 30 TC 12 Z9 12 U1 1 U2 4 PU HUMBOLDT FIELD RESEARCH INST PI STEUBEN PA PO BOX 9, STEUBEN, ME 04680-0009 USA SN 1528-7092 J9 SOUTHEAST NAT JI Southeast. Nat. PY 2004 VL 3 IS 1 BP 129 EP 138 DI 10.1656/1528-7092(2004)003[0129:DCAPHT]2.0.CO;2 PG 10 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 809RQ UT WOS:000220654200011 ER PT S AU Mashnik, SG Gudima, KK Moskalenko, IV Prael, RE Sierk, AJ AF Mashnik, SG Gudima, KK Moskalenko, IV Prael, RE Sierk, AJ BE Cucinotta, F Reitz, G TI CEM2K and LAQGSM codes as event generators for space-radiation-shielding and cosmic-ray-propagation applications SO SPACE LIFE SCIENCES: RADIATION RISK ASSESSMENT AND RADIATION MEASUREMENT IN LOW EARTH ORBIT SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE space radiation shielding; cosmic rays; CEM2k and LAQGSM codes; astrophysics ID CROSS-SECTIONS; NUCLEAR-REACTIONS; GEV PROTONS; MODEL; FRAGMENTATION; COLLISIONS; HYDROGEN; GALAXY; YIELDS AB The CEM2k and LAQGSM codes have been recently developed at Los Alamos National Laboratory to simulate nuclear reactions for a number of applications. We have benchmarked our codes against most available data measured at incident particle energies from 10 MeV to 800 GeV and have compared our results with predictions of other current models used by the nuclear community. Here, we present a brief description of our codes and show some illustrative results that testify that CEM2k and LAQGSM can be used as reliable event generators for space-radiation-shielding, cosmic-ray (CR) propagation, and other astro-physical applications. Finally, we show an example of combining of our calculated cross-sections with experimental data from our LANL T-16 compilation to produce evaluated files. Such evaluated files were successfully used in the model of particle propagation in the Galaxy GALPROP to better constrain the size of the CR halo. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Moldavian Acad Sci, Inst Appl Phys, MD-2028 Kishinev, Moldova. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. RP Los Alamos Natl Lab, Mailstop B283, Los Alamos, NM 87545 USA. EM mashnik@lanl.gov RI Moskalenko, Igor/A-1301-2007 OI Moskalenko, Igor/0000-0001-6141-458X NR 46 TC 26 Z9 26 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2004 VL 34 IS 6 BP 1288 EP 1296 DI 10.1016/j.asr.2003.08.057 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Biophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Biophysics; Geology; Meteorology & Atmospheric Sciences GA BBH88 UT WOS:000225592600003 PM 15880916 ER PT S AU Wilson, JW Tripathi, RK Qualls, GD Cucinotta, FA Prael, RE Norbury, JW Heinbockel, JH Tweed, J AF Wilson, JW Tripathi, RK Qualls, GD Cucinotta, FA Prael, RE Norbury, JW Heinbockel, JH Tweed, J BE Cucinotta, F Reitz, G TI A space radiation transport method development SO SPACE LIFE SCIENCES: RADIATION RISK ASSESSMENT AND RADIATION MEASUREMENT IN LOW EARTH ORBIT SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE radiation constraints; space radiation transport; spacecrafting shield design; HZETRN ID SHUTTLE; FRAGMENTATION; PROPAGATION; ISSUES; DEPTH; WATER; NE-20; MODEL; IONS AB Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from the preliminary design concepts to the final design. In particular, we will discuss the progress towards a full three-dimensional and computationally efficient deterministic code for which the current HZETRN evaluates the lowest-order asymptotic term. HZETRN is the first deterministic solution to the Boltzmann equation allowing field mapping within the International Space Station (ISS) in tens of minutes using standard finite element method (FEM) geometry common to engineering design practice enabling development of integrated multidisciplinary design optimization methods. A single ray trace in ISS FEM geometry requires 14 ms and severely limits application of Monte Carlo methods to such engineering models. A potential means of improving the Monte Carlo efficiency in coupling to spacecraft geometry is given in terms of re-configurable computing and could be utilized in the final design as verification of the deterministic method optimized design. Published by Elsevier Ltd on behalf of COSPAR. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Los Alamos Natl Lab, US DOE, Los Alamos, NM 87545 USA. Univ Wisconsin, Milwaukee, WI 53201 USA. Old Dominion Univ, Norfolk, VA 23508 USA. RP Wilson, JW (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM john.w.wilson@nasa.gov NR 52 TC 7 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2004 VL 34 IS 6 BP 1319 EP 1327 DI 10.1016/j.asr.2003.10.048 PG 9 WC Engineering, Aerospace; Astronomy & Astrophysics; Biophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Biophysics; Geology; Meteorology & Atmospheric Sciences GA BBH88 UT WOS:000225592600007 PM 15880919 ER PT S AU Antonelli, F Belli, M Campa, A Chatterjee, A Dini, V Esposito, G Rydberg, B Simone, G Tabocchini, MA AF Antonelli, F Belli, M Campa, A Chatterjee, A Dini, V Esposito, G Rydberg, B Simone, G Tabocchini, MA BE Cucinotta, F Reitz, G TI DNA fragmentation induced by Fe ions in human cells: shielding influence on spatially correlated damage SO SPACE LIFE SCIENCES: RADIATION RISK ASSESSMENT AND RADIATION MEASUREMENT IN LOW EARTH ORBIT SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE radiation risk; DNA fragmentation; Fe ions in human cells; radiation shielding; radiation dose ID LIGHT-IONS; SPACE AB Outside the magnetic field of the Earth, high energy heavy ions constitute a relevant part of the biologically significant dose to astronauts during the very long travels through space. The typical pattern of energy deposition in the matter by heavy ions on the microscopic scale is believed to produce spatially correlated damage in the DNA which is critical for radiobiological effects. We have investigated the influence of a Incite shielding on the initial production of very small DNA fragments in human fibroblasts irradiated with 1 GeV/u iron (Fe) ions. We also used gamma-rays as reference radiation. Our results show: (1) a lower effect per incident ion when the shielding is used; (2) an higher DNA Double Strand Breaks (DSB) induction by Fe ions than by gamma-rays in the size range 1-23 kbp; (3) a non-random DNA DSB induction by Fe ions. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Ist Super Sanita, I-00161 Rome, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Antonelli, F (reprint author), Ist Super Sanita, Viale Regina Elena 299, I-00161 Rome, Italy. EM francesca.antonelli@iss.it RI Dini, Valentina/A-3147-2009; Antonelli, Francesca/A-4446-2009; Simone, Giustina/F-3799-2010; Tabocchini, Maria Antonella/A-4035-2010; esposito, giuseppe/I-5830-2014; ESPOSITO, GIUSEPPE/F-2116-2015 OI Tabocchini, Maria Antonella/0000-0003-3244-6106; NR 13 TC 12 Z9 12 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2004 VL 34 IS 6 BP 1353 EP 1357 DI 10.1016/j.asr.2003.11.020 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Biophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Biophysics; Geology; Meteorology & Atmospheric Sciences GA BBH88 UT WOS:000225592600012 PM 15880923 ER PT S AU Koniarek, JP Thomas, JL Vazquez, M AF Koniarek, JP Thomas, JL Vazquez, M BE Cucinotta, F Reitz, G TI Detection of microlesions induced by heavy ions using liposomes filled with fluorescent dye SO SPACE LIFE SCIENCES: RADIATION RISK ASSESSMENT AND RADIATION MEASUREMENT IN LOW EARTH ORBIT SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE radiation risk; detection of microlesions; heavy ions; fluorescent dye; cell irradiation ID EXTRUSION AB In cells irradiation by heavy ions has been hypothesized to produce microlesions, regions of local damage. In cell membranes this damage is thought to manifest itself in the form of holes. The primary evidence for microlesions comes from morphological studies of cell membranes, but this evidence is still controversial, especially since holes also have been observed in membranes of normal, nonirradiated, cells. However, it is possible that damage not associated with histologically discernable disruptions may still occur. In order to resolve this issue, we developed a system for detecting microlesions based on liposomes filled with fluorescent dye. We hypothesized that if microlesions form in these liposomes as the result of irradiation, then the entrapped dye will leak out into the surrounding medium in a measurable way. Polypropylene vials containing suspensions of vesicles composed of either dipalmitoyl phosphatidylcholine, or a combination of egg phosphatidylcholine and cholesterol were irradiated at the Brookhaven National Laboratory using Fe-56 ions at 1 GeV/amu. In several cases we obtained a significant loss of the entrapped dye above the background level. Our results suggest that holes may form in liposomes as the result of heavy ion irradiation, and that these holes are large enough to allow leakage of cell internal contents that are at least as large as a 1 nm diameter calcein molecule. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Columbia Univ, Dept Ophthalmol, New York, NY 10032 USA. Columbia Univ, Dept Chem Engn, New York, NY 10027 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Koniarek, JP (reprint author), Columbia Univ, Dept Ophthalmol, 630 W 168th St, New York, NY 10032 USA. EM jk24@columbia.edu NR 12 TC 5 Z9 5 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2004 VL 34 IS 6 BP 1373 EP 1377 DI 10.1016/j.asr.2004.01.012 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Biophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Biophysics; Geology; Meteorology & Atmospheric Sciences GA BBH88 UT WOS:000225592600016 PM 15881776 ER PT S AU Sannita, WG Acquaviva, M Ball, SL Belli, F Bisti, S Bidoli, V Carozzo, S Casolino, M Cucinotta, F De Pascale, MP Di Fino, L Di Marco, S Maccarone, R Martello, C Miller, J Narici, L Peachey, NS Picozza, P Rinaldi, A Ruggieri, D Saturno, M Schardt, D Vazquez, M AF Sannita, WG Acquaviva, M Ball, SL Belli, F Bisti, S Bidoli, V Carozzo, S Casolino, M Cucinotta, F De Pascale, MP Di Fino, L Di Marco, S Maccarone, R Martello, C Miller, J Narici, L Peachey, NS Picozza, P Rinaldi, A Ruggieri, D Saturno, M Schardt, D Vazquez, M BE Horneck, G LevasseurRegourd, AC Rabin, BM Slenzka, KB TI Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project SO SPACE LIFE SCIENCES: SEARCH FOR SIGNATURES OF LIFE, AND SPACE FLIGHT ENVIRONMENTAL EFFECTS ON THE NERVOUS SYSTEM SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE the ALTEA-MICE project; visual impairment; heavy ions ID LIGHT-FLASHES; NITROGEN NUCLEI; RAY; ASTRONAUTS; RADIATION; SPACE; EYE; RETINA; MUONS AB ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories (BNL] (Upton, NY, USA) and the Gesellschaft fur Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, ERG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Ist Nazl Fis Nucl Roma 2, Rome, Italy. Univ Genoa, Dept Motor Sci, Genoa, Italy. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Cleveland Clin Fdn, Cole Eye Inst, Cleveland, OH 44195 USA. Cleveland VAMC, Cleveland, OH USA. Univ Roma Tor Vergata, Dept Phys, Rome, Italy. Univ Aquila, Inst Physiol, I-67100 Laquila, Italy. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. GSI Darmstadt, D-6100 Darmstadt, Germany. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Sannita, WG (reprint author), Ist Nazl Fis Nucl Roma 2, Rome, Italy. EM 29537@unige.it RI Peachey, Neal/G-5533-2010; Di Marco, Stefano/C-6386-2009; Schardt, Dieter/M-1517-2014; OI Di Marco, Stefano/0000-0003-4847-6270; Schardt, Dieter/0000-0001-7851-5993; Ball, Sherry/0000-0002-2362-9499; MACCARONE, Rita/0000-0003-0648-3771; casolino, marco/0000-0001-6067-5104; Picozza, Piergiorgio/0000-0002-7986-3321; CAROZZO, Simone/0000-0003-4536-9832 NR 24 TC 7 Z9 8 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES PY 2004 VL 33 IS 8 BP 1347 EP 1351 DI 10.1016/j.asr.2003.11.007 PG 5 WC Engineering, Aerospace; Astronomy & Astrophysics; Biophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Biophysics; Geology; Meteorology & Atmospheric Sciences GA BAF41 UT WOS:000222000200022 PM 15803626 ER PT S AU Narici, L Belli, F Bidoli, V Casolino, M De Pascale, MP Di Fino, L Furano, G Modena, I Morselli, A Picozza, P Reali, E Rinaldi, A Ruggieri, D Sparvoli, R Zaconte, V Sannita, WG Carozzo, S Licoccia, S Romagnoli, P Traversa, E Cotronei, V Vazquez, M Miller, J Salnitskii, VP Shevchenko, OI Petrov, VP Trukhanov, KA Galper, A Khodarovich, A Korotkov, MG Popov, A Vavilov, N Avdeev, S Boezio, M Bonvicini, W Vacchi, A Zampa, N Mazzenga, G Ricci, M Spillantini, P Castellini, G Vittori, R Carlson, P Fuglesang, C Schardt, D AF Narici, L Belli, F Bidoli, V Casolino, M De Pascale, MP Di Fino, L Furano, G Modena, I Morselli, A Picozza, P Reali, E Rinaldi, A Ruggieri, D Sparvoli, R Zaconte, V Sannita, WG Carozzo, S Licoccia, S Romagnoli, P Traversa, E Cotronei, V Vazquez, M Miller, J Salnitskii, VP Shevchenko, OI Petrov, VP Trukhanov, KA Galper, A Khodarovich, A Korotkov, MG Popov, A Vavilov, N Avdeev, S Boezio, M Bonvicini, W Vacchi, A Zampa, N Mazzenga, G Ricci, M Spillantini, P Castellini, G Vittori, R Carlson, P Fuglesang, C Schardt, D BE Horneck, G LevasseurRegourd, AC Rabin, BM Slenzka, KB TI The ALTEA/ALTEINO projects: studying functional effects of microgravity and cosmic radiation SO SPACE LIFE SCIENCES: SEARCH FOR SIGNATURES OF LIFE, AND SPACE FLIGHT ENVIRONMENTAL EFFECTS ON THE NERVOUS SYSTEM SE ADVANCES IN SPACE RESEARCH-SERIES LA English DT Article; Proceedings Paper CT 2nd World Space Congress/34th COSPAR Scientific Assembly CY OCT 10-19, 2002 CL HOUSTON, TX SP Comm Space Res DE The ALTEA/ALTEINO projects; functional effects of microgravity and cosmic radiation ID LIGHT-FLASHES; NITROGEN NUCLEI; RAY; SPACE; ASTRONAUTS; EYE AB The ALTEA project investigates the risks of functional brain damage induced by particle radiation in space. A modular facility (the ALTEA facility) is being implemented and will be operated in the International Space Station (ISS) to record electrophysiological and behavioral descriptors of brain function and to monitor their time dynamics and correlation with particles and space environment. The focus of the program will be on abnormal visual perceptions (often reported as "light flashes" by astronauts) and the impact on retinal and brain visual structures of particle in microgravity conditions. The facility will be made available to the international scientific community for human neurophysiological, electrophysiological and psychophysics experiments, studies on particle fluxes, and dosimetry. A precursor of ALTEA (the 'Alteino' project) helps set the experimental baseline for the ALTEA experiments, while providing novel information on the radiation environment onboard the ISS and on the brain electrophysiology of the astronauts during orbital flights. Alteino was flown to the ISS on the Soyuz TM34 as part of mission Marco Polo. Controlled ground experiments using mice and accelerator beams complete the experimental strategy of ALTEA. We present here the status of progress of the ALTEA project and preliminary results of the Alteino study on brain dynamics, particle fluxes and abnormal visual perceptions. (C) 2004 COSPAR. Published by Elsevier Ltd. All rights reserved. C1 Univ Roma Tor Vergata, Dept Phys, I-00133 Rome, Italy. INFM Roma2, I-00133 Rome, Italy. Univ Genoa, DISM, I-16126 Genoa, Italy. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Univ Roma Tor Vergata, Dept Sci & Chem Technol, Rome, Italy. Italian Space Agcy, Rome, Italy. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Minist Publ Hlth Russia, Inst Biomed Problems, Moscow, Russia. Moscow State Engn Phys Inst, Moscow, Russia. Russian Space Corp Energia, Korolev, Moscow Region, Russia. Univ Trieste, Dept Phys, I-34127 Trieste, Italy. Ist Nazl Fis Nucl, Trieste, Italy. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Florence, Dept Phys, I-50121 Florence, Italy. Ist Nazl Fis Nucl, I-50125 Florence, Italy. CNR, IROE, I-50127 Florence, Italy. Ist Nazl Fis Nucl, I-06100 Perugia, Italy. ESA, F-75738 Paris 15, France. Royal Inst Technol, Stockholm, Sweden. GSI Darmstadt, D-6100 Darmstadt, Germany. RP Narici, L (reprint author), Univ Roma Tor Vergata, Dept Phys, Via Ric Scientipica 1, I-00133 Rome, Italy. EM livio.narici@roma2.infn.it RI Morselli, Aldo/G-6769-2011; Traversa, Enrico/E-4547-2011; Vacchi, Andrea/C-1291-2010; Schardt, Dieter/M-1517-2014; Galper, Arkady/M-9610-2015; OI Boezio, Mirko/0000-0002-8015-2981; Morselli, Aldo/0000-0002-7704-9553; CAROZZO, Simone/0000-0003-4536-9832; Vacchi, Andrea/0000-0003-3855-5856; Schardt, Dieter/0000-0001-7851-5993; casolino, marco/0000-0001-6067-5104; Castellini, Guido/0000-0002-0177-0643; Sparvoli, Roberta/0000-0002-6314-6117; Picozza, Piergiorgio/0000-0002-7986-3321 NR 15 TC 21 Z9 21 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI KIDLINGTON PA THE BOULEVARD, LANGFORD LANE,, KIDLINGTON OX5 1GB, OXFORD, ENGLAND SN 0273-1177 J9 ADV SPACE RES-SERIES PY 2004 VL 33 IS 8 BP 1352 EP 1357 DI 10.1016/j.asr.2003.09.052 PG 6 WC Engineering, Aerospace; Astronomy & Astrophysics; Biophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Biophysics; Geology; Meteorology & Atmospheric Sciences GA BAF41 UT WOS:000222000200023 PM 15803627 ER PT J AU Young, DT Berthelier, JJ Blanc, M Burch, JL Coates, AJ Goldstein, R Grande, M Hill, TW Johnson, RE Kelha, V McComas, DJ Sittler, EC Svenes, KR Szego, K Tanskanen, P Ahola, K Anderson, D Bakshi, S Baragiola, RA Barraclough, L Black, RK Bolton, S Booker, T Bowman, R Casey, P Crary, FJ Delapp, D Dirks, G Eaker, N Funsten, H Furman, JD Gosling, JT Hannula, H Holmlund, C Huomo, H Illiano, JM Jensen, P Johnson, MA Linder, DR Luntama, T Maurice, S McCabe, KP Mursula, K Narheim, BT Nordholt, JE Preece, A Rudzki, J Ruitberg, A Smith, K Szalai, S Thomsen, MF Viherkanto, K Vilppola, J Vollmer, T Wahl, TE Wuest, M Ylikorpi, T Zinsmeyer, C AF Young, DT Berthelier, JJ Blanc, M Burch, JL Coates, AJ Goldstein, R Grande, M Hill, TW Johnson, RE Kelha, V McComas, DJ Sittler, EC Svenes, KR Szego, K Tanskanen, P Ahola, K Anderson, D Bakshi, S Baragiola, RA Barraclough, L Black, RK Bolton, S Booker, T Bowman, R Casey, P Crary, FJ Delapp, D Dirks, G Eaker, N Funsten, H Furman, JD Gosling, JT Hannula, H Holmlund, C Huomo, H Illiano, JM Jensen, P Johnson, MA Linder, DR Luntama, T Maurice, S McCabe, KP Mursula, K Narheim, BT Nordholt, JE Preece, A Rudzki, J Ruitberg, A Smith, K Szalai, S Thomsen, MF Viherkanto, K Vilppola, J Vollmer, T Wahl, TE Wuest, M Ylikorpi, T Zinsmeyer, C TI Cassini Plasma Spectrometer investigation SO SPACE SCIENCE REVIEWS LA English DT Review DE Saturn; Titan; magnetosphere; space plasma; ion composition ID ION MASS-SPECTROMETER; ULTRATHIN CARBON FOILS; SATURNS E-RING; TITANS IONOSPHERE; SOLAR-WIND; PICKUP IONS; WATER ICE; ELECTROSTATIC ANALYZERS; NEUTRAL GAS; MHD MODEL AB The Cassini Plasma Spectrometer (CAPS) will make comprehensive three-dimensional mass-resolved measurements of the full variety of plasma phenomena found in Saturn's magnetosphere. Our fundamental scientific goals are to understand the nature of saturnian plasmas primarily their sources of ionization, and the means by which they are accelerated, transported, and lost. In so doing the CAPS investigation will contribute to understanding Saturn's magnetosphere and its complex interactions with Titan, the icy satellites and rings, Saturn's ionosphere and aurora, and the solar wind. Our design approach meets these goals by emphasizing two complementary types of measurements: high-time resolution velocity distributions of electrons and all major ion species; and lower-time resolution, high-mass resolution spectra of all ion species. The CAPS instrument is made up of three sensors: the Electron Spectrometer (ELS), the Ion Beam Spectrometer (IBS), and the Ion Mass Spectrometer (IMS). The ELS measures the velocity distribution of electrons from 0.6 eV to 28,250 keV, a range that permits coverage of thermal electrons found at Titan and near the ring plane as well as more energetic trapped electrons and auroral particles. The IBS measures ion velocity distributions with very high angular and energy resolution from 1 eV to 49,800 keV. It is specially designed to measure sharply defined ion beams expected in the solar wind at 9.5 AU, highly directional rammed ion fluxes encountered in Titan's ionosphere, and anticipated field-aligned auroral fluxes. The IMS is designed to measure the composition of hot, diffuse magnetospheric plasmas and low-concentration ion species 1 eV to 50,280 eV with an atomic resolution M/DeltaM similar to70 and, for certain molecules., (such as N(2)(+) and CO(+)) effective resolution as high as similar to2500. The three sensors are mounted on a motor-driven actuator that rotates the entire instrument over approximately one-half of the sky every 3 min. C1 SW Res Inst, San Antonio, TX 78228 USA. Los Alamos Natl Lab, Los Alamos, NM USA. CNRS, Ctr Etud Environm Terr & Planetaires, St Maur, France. Observ Midi Pyrenees, F-31400 Toulouse, France. UCL, Mullard Space Sci Lab, Surrey, England. Jet Prop Lab, Pasadena, CA USA. Rutherford Appleton Lab, Didcot, Oxon, England. Rice Univ, Houston, TX 77251 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Virginia, Charlottesville, VA USA. VTT Informat Technol, Espoo, Finland. Norwegian Def Res Estab, N-2007 Kjeller, Norway. KFKI Res Inst Particle & Nucl Phys, Budapest, Hungary. Univ Oulu, Oulu, Finland. Nokia Electr Ltd, Helsinki, Finland. TEKES Technol Dev Ctr, Helsinki, Finland. RP Young, DT (reprint author), SW Res Inst, San Antonio, TX 78228 USA. RI Coates, Andrew/C-2396-2008; Mursula, Kalevi/L-8952-2014; Funsten, Herbert/A-5702-2015; Grande, Manuel/C-2242-2013 OI Coates, Andrew/0000-0002-6185-3125; Mursula, Kalevi/0000-0003-4892-5056; Funsten, Herbert/0000-0002-6817-1039; Grande, Manuel/0000-0002-2233-2618 NR 129 TC 305 Z9 305 U1 3 U2 24 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2004 VL 114 IS 1-4 BP 1 EP 112 DI 10.1007/s11214-004-1406-4 PG 112 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904BY UT WOS:000227472300002 ER PT J AU Cheng, CZ AF Cheng, CZ TI Physics of substorm growth phase, onset, and dipolarization SO SPACE SCIENCE REVIEWS LA English DT Review ID THIN CURRENT SHEET; FIELD-ALIGNED CURRENTS; COLLISIONLESS BALLOONING MODES; LOW-FREQUENCY PERTURBATIONS; MAGNETOTAIL CURRENT SHEET; NEAR-EARTH MAGNETOTAIL; PLASMA SHEET; CURRENT DISRUPTION; MAGNETOSPHERIC SUBSTORMS; MAGNETIC RECONNECTION AB A new scenario of substorm growth phase, onset and dipolarization during expansion phase and the corresponding physical processes are presented. During the growth phase, as a result of enhanced plasma convection, the plasma pressure and its gradient continue to be enhanced over the quiet-time values in the plasma sheet. Toward the late growth phase, a strong cross-tail current sheet is formed in the near-Earth plasma sheet region, where a local magnetic well is formed. The equatorial plasma beta (beta(eq)) can reach a local maximum with value larger than 50 and the cross-tail current density can be enhanced to over 10nA/m(2) as obtained from 3D quasi-static magnetospheric equilibrium solutions for the growth phase. The most unstable kinetic ballooning instabilities (KBI) are expected to be located in the tailward side of the strong cross-tail current sheet region. The field lines in the most unstable KBI region map to the transition region between the region-l and region-2 currents in the ionosphere, which is consistent with the observed initial brightening location of the breakup arc in the intense proton precipitation region. The KBI explains the AMPTE/CCE observations that a low frequency instability with a wave period of 50 - 75 seconds is excited about 2 - 3 min prior to substorm onset and grows exponentially to a large amplitude at the onset of current disruption ( or current reduction). At the onset of current disruption higher frequency instabilities are excited so that the plasma and electromagnetic field fluctuations form a strong turbulent state. Plasma transport takes place due to the strong turbulence to relax the ambient plasma pressure profile so that the plasma pressure and current density are reduced and the ambient magnetic field intensity increases by more than a factor of 2 - 3 in the high-beta(eq) region and the field line geometry recovers from tail-like to dipole-like - dipolarization. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Cheng, Chio/K-1005-2014 NR 125 TC 42 Z9 43 U1 2 U2 6 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 EI 1572-9672 J9 SPACE SCI REV JI Space Sci. Rev. PY 2004 VL 113 IS 1-2 BP 207 EP 270 DI 10.1023/B:SPAC.0000042943.59976.0e PG 64 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 857FH UT WOS:000224101100006 ER PT J AU Saunders, RS Arvidson, RE Badhwar, GD Boynton, WV Christensen, PR Cucinotta, FA Feldman, WC Gibbs, RG Kloss, C Landano, MR Mase, RA McSmith, GW Meyer, MA Mitrofanov, IG Pace, GD Plaut, JJ Sidney, WP Spencer, DA Thompson, TW Zeitlin, CJ AF Saunders, RS Arvidson, RE Badhwar, GD Boynton, WV Christensen, PR Cucinotta, FA Feldman, WC Gibbs, RG Kloss, C Landano, MR Mase, RA McSmith, GW Meyer, MA Mitrofanov, IG Pace, GD Plaut, JJ Sidney, WP Spencer, DA Thompson, TW Zeitlin, CJ TI 2001 Mars Odyssey mission summary SO SPACE SCIENCE REVIEWS LA English DT Review ID DEPOSITS; HYDROGEN AB The 2001 Mars Odyssey spacecraft, now in orbit at Mars, will observe the Martian surface at infrared and visible wavelengths to determine surface mineralogy and morphology, acquire global gamma ray and neutron observations for a full Martian year, and study the Mars radiation environment from orbit. The science objectives of this mission are to: ( 1) globally map the elemental composition of the surface, ( 2) determine the abundance of hydrogen in the shallow subsurface, ( 3) acquire high spatial and spectral resolution images of the surface mineralogy, ( 4) provide information on the morphology of the surface, and ( 5) characterize the Martian near-space radiation environment as related to radiation-induced risk to human explorers. To accomplish these objectives, the 2001 Mars Odyssey science payload includes a Gamma Ray Spectrometer (GRS), a multi-spectral Thermal Emission Imaging System (THEMIS), and a radiation detector, the Martian Radiation Environment Experiment (MARIE). THEMIS and MARIE are mounted on the spacecraft with THEMIS pointed at nadir. GRS is a suite of three instruments: a Gamma Subsystem (GSS), a Neutron Spectrometer (NS) and a High-Energy Neutron Detector (HEND). The HEND and NS instruments are mounted on the spacecraft body while the GSS is on a 6-m boom. Some science data were collected during the cruise and aerobraking phases of the mission before the prime mission started. THEMIS acquired infrared and visible images of the Earth-Moon system and of the southern hemisphere of Mars. MARIE monitored the radiation environment during cruise. The GRS collected calibration data during cruise and aerobraking. Early GRS observations in Mars orbit indicated a hydrogen-rich layer in the upper meter of the subsurface in the Southern Hemisphere. Also, atmospheric densities, scale heights, temperatures, and pressures were observed by spacecraft accelerometers during aerobraking as the spacecraft skimmed the upper portions of the Martian atmosphere. This provided the first in-situ evidence of winter polar warming in the Mars upper atmosphere. The prime mission for 2001 Mars Odyssey began in February 2002 and will continue until August 2004. During this prime mission, the 2001 Mars Odyssey spacecraft will also provide radio relays for the National Aeronautics and Space Administration ( NASA) and European landers in early 2004. Science data from 2001 Mars Odyssey instruments will be provided to the science community via NASA's Planetary Data System (PDS). The first PDS release of Odyssey data was in October 2002; subsequent releases occur every 3 months. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Arizona, Dept Planetary Sci, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. NASA Headquarters, Washington, DC 20546 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Russian Aviat & Space Agcy, Inst Space Res, Lab Space Gamma Ray Spect, Moscow, Russia. Lockheed Martin Astronaut, Denver, CO 80201 USA. Baylor Coll Med, Natl Space Biomed Res Inst, Houston, TX 77030 USA. RP Plaut, JJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM plaut@jpl.nasa.gov NR 26 TC 35 Z9 35 U1 3 U2 21 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2004 VL 110 IS 1-2 BP 1 EP 36 DI 10.1023/B:SPAC.0000021006.84299.18 PG 36 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 806AI UT WOS:000220406400002 ER PT J AU Boynton, WV Feldman, WC Mitrofanov, IG Evans, LG Reedy, RC Squyres, SW Starr, R Trombka, JI D'Uston, C Arnold, JR Englert, PAJ Metzger, AE Wanke, H Bruckner, J Drake, DM Shinohara, C Fellows, C Hamara, DK Harshman, K Kerry, K Turner, C Ward, M Barthe, H Fuller, KR Storms, SA Thornton, GW Longmire, JL Litvak, ML Ton'chev, AK AF Boynton, WV Feldman, WC Mitrofanov, IG Evans, LG Reedy, RC Squyres, SW Starr, R Trombka, JI D'Uston, C Arnold, JR Englert, PAJ Metzger, AE Wanke, H Bruckner, J Drake, DM Shinohara, C Fellows, C Hamara, DK Harshman, K Kerry, K Turner, C Ward, M Barthe, H Fuller, KR Storms, SA Thornton, GW Longmire, JL Litvak, ML Ton'chev, AK TI The Mars Odyssey Gamma-Ray Spectrometer instrument suite SO SPACE SCIENCE REVIEWS LA English DT Review ID LUNAR NEUTRON-FLUX; CHEMICAL-COMPOSITION; ELEMENTAL COMPOSITION; GERMANIUM DETECTORS; PLANETARY SURFACES; RADIATION-DAMAGE; LANDING SITE; 433 EROS; SPECTROSCOPY; SUBSURFACE AB The Mars Odyssey Gamma-Ray Spectrometer is a suite of three different instruments, a gamma subsystem (GS), a neutron spectrometer, and a high-energy neutron detector, working together to collect data that will permit the mapping of elemental concentrations on the surface of Mars. The instruments are complimentary in that the neutron instruments have greater sensitivity to low amounts of hydrogen, but their signals saturate as the hydrogen content gets high. The hydrogen signal in the GS, on the other hand, does not saturate at high hydrogen contents and is sensitive to small differences in hydrogen content even when hydrogen is very abundant. The hydrogen signal in the neutron instruments and the GS have a different dependence on depth, and thus by combining both data sets we can infer not only the amount of hydrogen, but constrain its distribution with depth. In addition to hydrogen, the GS determines the abundances of several other elements. The instruments, the basis of the technique, and the data processing requirements are described as are some expected applications of the data to scientific problems. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Space Res Inst, Moscow, Russia. Comp Sci Corp, Sci Programs, Lanham, MD 20706 USA. Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ctr Etud Spatiale Rayonnements, Toulouse, France. Univ Calif San Diego, Dept Chem, La Jolla, CA 92093 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Chem, D-55128 Mainz, Germany. Techsource, Santa Fe, NM 87505 USA. RP Boynton, WV (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. EM WBoynton@GAMMA1.lpl.arizona.edu OI Reedy, Robert/0000-0002-2189-1303 NR 77 TC 134 Z9 135 U1 3 U2 14 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2004 VL 110 IS 1-2 BP 37 EP 83 DI 10.1023/B:SPAC.0000021007.76126.15 PG 47 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 806AI UT WOS:000220406400003 ER PT J AU Saganti, PB Cucinotta, FA Wilson, JW Simonsen, LC Zeitlin, C AF Saganti, PB Cucinotta, FA Wilson, JW Simonsen, LC Zeitlin, C TI Radiation climate map for analyzing risks to astronauts on the Mars surface from galactic cosmic rays SO SPACE SCIENCE REVIEWS LA English DT Review ID SPACE RADIATION; EXPLORATION; EXPOSURE; MODEL AB The potential risks for late effects including cancer, cataracts, and neurological disorders due to exposures to the galactic cosmic rays (GCR) is a large concern for the human exploration of Mars. Physical models are needed to project the radiation exposures to be received by astronauts in transit to Mars and on the Mars surface, including the understanding of the modification of the GCR by the Martian atmosphere and identifying shielding optimization approaches. The Mars Global Surveyor (MGS) mission has been collecting Martian surface topographical data with the Mars Orbiter Laser Altimeter (MOLA). Here we present calculations of radiation climate maps of the surface of Mars using the MOLA data, the radiation transport model HZETRN ( high charge and high energy transport), and the quantum multiple scattering fragmentation model, QMSFRG. Organ doses and the average number of particle hits per cell nucleus from GCR components ( protons, heavy ions, and neutrons) are evaluated as a function of the altitude on the Martian surface. Approaches to improve the accuracy of the radiation climate map, presented here using data from the 2001 Mars Odyssey mission, are discussed. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Lockheed Martin, Space Operat, Houston, TX 77058 USA. RP Saganti, PB (reprint author), A&M Univ, NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. EM premkumeur.saqanti1@jsc.nasa.gov NR 22 TC 34 Z9 34 U1 2 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-6308 J9 SPACE SCI REV JI Space Sci. Rev. PY 2004 VL 110 IS 1-2 BP 143 EP 156 DI 10.1023/B:SPAC.0000021010.20082.1a PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 806AI UT WOS:000220406400006 ER PT S AU Hatchell, BK Harper, WW Schultz, JF AF Hatchell, BK Harper, WW Schultz, JF BE Peterson, LD Guyer, RC TI Fieldable Fourier transform spectrometer SO SPACE SYSTEMS ENGINEERING AND OPTICAL ALIGNMENT MECHANISMS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Space Systems Engineering and Optical Alignment Mechanisms CY AUG 04-06, 2004 CL Denver, CO SP SPIE DE quantum cascade lasers; chemical sensing; frequency modulation LIDAR; remote sensing AB The infrared sensors group at the Pacific Northwest National Laboratory (PNNL) is focused on the science and technology of remote and in-situ chemical sensors for detecting proliferation and countering terrorism. To support these vital missions, PNNL is developing frequency-modulation techniques for remote probing over long optical paths by means of differential-absorption light detecting and ranging (LIDAR). This technique can easily monitor large areas, or volumes, that could only be accomplished with a large network of point sensors. Recently, PNNL began development of a rugged frequency-modulation differential-absorption LIDAR (FM-DIAL) system to conduct field experiments. To provide environmental protection for the system and facilitate field deployments and operations, a large, well insulated, temperature controlled trailer was specified and acquired. The trailer was outfitted with a shock-mounted optical bench, an electronics rack, a liquid nitrogen Dewar, and a power generator. A computer-controlled gimbal-mounted mirror was added to allow the telescope beam to be accurately pointed in both the vertical and horizontal plane. This turned out to be the most complicated addition, and is described in detail. This paper provides an overview of the FM-DIAL system and illustrates innovative solutions developed to overcome several alignment and stability issues encountered in the field. C1 PNNL, Richland, WA 99352 USA. RP Hatchell, BK (reprint author), PNNL, POB 999,902 Battelle Blvd, Richland, WA 99352 USA. NR 3 TC 0 Z9 0 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5466-4 J9 P SOC PHOTO-OPT INS PY 2004 VL 5528 BP 342 EP 352 DI 10.1117/12.562576 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BBC27 UT WOS:000224727800033 ER PT S AU Matonic, J Brown, J Foltyn, L Garcia, L Hart, R Herman, D Huling, J Pansoy-Hjelvik, MEL Sandoval, F Spengler, D AF Matonic, J Brown, J Foltyn, L Garcia, L Hart, R Herman, D Huling, J Pansoy-Hjelvik, MEL Sandoval, F Spengler, D BE ElGenk, MS TI Heat source neutron emission rate reduction studies water induced HF liberation SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB Plutonium-238 oxide ((PUO2)-P-238) is Used in the fabrication of general purpose heat sources (GPHS) or light-weight radioisotope heater units (LWRHUs). The heat sources supply the thermal energy used in radioisotope thermoelectric generators to power spacecraft for deep space missions and to heat critical components in the cold environs of space. Los Alamos National Laboratory has manufactured heat sources for approximately two decades. The aqueous purification of (PUO2)-P-238 is required, due to rigorous total Pu-content, actinide and non-actinide metal impurity, and neutron emission rate specifications. The (PUO2)-P-238 aqueous purification process is a new capability at Los Alamos National Laboratory as previously, aqueous purified (PUO2)-P-238 occurred at other DOE complexes. The Pu-content and actinide and non-actinide metal impurity specifications are met well within specification in the Los Alamos process, though reduction in neutron emission rates have been challenging, High neutron emission rates are typically attributed to fluoride content in the oxide. The alpha decay from Pu-238 results in alpha,n reactions with light elements such as O-17, O-18, and F-19 resulting in high neutron emission rates in the purified (PuO2)-Pu-238. Simple O-16-exchange takes care of the high NER due to O-17, and O-18. A new method to reduce the NER due to F-19 in the purified (PUO2)-P-238 is presented in this paper. The method involves addition of water to purified (PUO2)-P-238, followed by heating to remove the water and liberating fluoride as HF. C1 Los Alamos Natl Lab, Pu Sci & Engn Grp NMT 9, Nucl Mat & Technol Div, Los Alamos, NM 87545 USA. RP Matonic, J (reprint author), Los Alamos Natl Lab, Pu Sci & Engn Grp NMT 9, Nucl Mat & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 242 EP 247 PG 6 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600030 ER PT S AU Hixson, LL Houts, MG Clement, SD AF Hixson, LL Houts, MG Clement, SD BE ElGenk, MS TI Technical bases to aid in the decision of conducting full power ground nuclear tests for space fission reactors SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB The extent to which, if any, full power ground nuclear testing of space reactors should be performed has been a point of discussion within the industry for decades. Do the benefits outweigh the risks? Are there equivalent alternatives? Can a test facility be constructed (or modified) in a reasonable amount of time? Is the test article an accurate representation of the flight system? Are the costs too restrictive? The obvious benefits of full power ground nuclear testing; obtaining systems integrated reliability data on a full-scale, complete end-to-end system; come at some programmatic risk. Safety related information is not obtained from a full-power ground nuclear test. This paper will discuss and assess these and other technical considerations essential in the decision to conduct full power ground nuclear-or alternative-tests. C1 Los Alamos Natl Lab, Ctr Space Sci & Explorat, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Ctr Space Sci & Explorat, MS-D466, Los Alamos, NM 87545 USA. EM lhixson@lanl.gov NR 13 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 308 EP 318 PG 11 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600038 ER PT S AU Conklin, JC Courville, GE Scott, JH AF Conklin, JC Courville, GE Scott, JH BE ElGenk, MS TI Evaluation of active working fluids for Brayton cycles in space applications SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB The main parameter of interest for space thermal power conversion to electricity is specific power, defined as the total electric power output per unit of system mass, rather than the cycle thermal efficiency. For a closed Brayton cycle, performance with two active working fluids, nitrogen tetroxide and aluminum chloride, is compared to that with an inert mixture of helium and xenon having a molecular mass of 40. A chemically active working fluid is defined here as a chemical compound that has a relatively high molecular weight at temperatures appropriate for the compressor inlet and dissociates to a lighter molecular weight fluid at typical turbine inlet temperatures. The active working fluids may have the advantage of a higher net turbomachinery work output and an advantageous enhancement of the heat transfer coefficient in the heat exchangers. The fundamental theory of the active working fluid concept is presented to demonstrate these potential advantages. Scoping calculations of the heat exchanger mass for a selected spacecraft application of 36.4 kW of electrical power output show that the nitrogen tetroxide active working fluid has an advantageous 7% to 30% lower mass-to-power ratio than that for the inert noble gas mixture, depending on the allowable turbine inlet temperature. The calculations for the aluminum chloride system suggest only a slight improvement in performance relative to the inert noble gas mixture. C1 Oak Ridge Natl Lab, Engn Sci & Technol Div, Oak Ridge, TN 37831 USA. RP Conklin, JC (reprint author), Oak Ridge Natl Lab, Engn Sci & Technol Div, Oak Ridge, TN 37831 USA. NR 16 TC 0 Z9 0 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 463 EP 472 PG 10 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600057 ER PT S AU Holcomb, DE Kisner, RA Roberts, MJ AF Holcomb, DE Kisner, RA Roberts, MJ BE ElGenk, MS TI Johnson noise thermometry for space reactor temperature measurement SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB A primary difference between terrestrial and remotely located reactors is the ability to periodically recalibrate and replace the instrumentation. Because of this, space reactors place a premium on self-calibrating, long-term reliable instrumentation. The primary temperature measurements for the SP-100 reactor were to be made using W/W-Re thermocouples. However, the large gamma and neutron dose expected at the coolant outlet (>1 MGy gamma; 3 x 10(15) fast neutron fluence) combined with the high temperature (1375 K nominal; 1650 K maximum) meant that the thermocouples would drift significantly over the lifetime of the reactor. A combined Johnson noise resistance thermometer capable of performing under these extreme conditions was developed by ORNL (Carroll, 1994). Johnson noise is a fundamental representation of temperature-it is the vibration of the electronic field surrounding atoms as they thermally vibrate. Johnson noise, however, is fundamentally a small signal (similar to4 x 10(-7) V-rms for a 100 Omega resistor at 300 K, using a 100 kHz bandwidth) spread throughout the frequency spectrum. Creating the electronics and signal processing required to effectively measure and interpret the noise signal remains challenging. ORNL has recently developed closely related Johnson Noise Thermometry (JNT) electronics and signal processing capabilities under a DOE International Nuclear Energy Research Initiative Project with the Korean Atomic Energy Research Institute (U.S. DOE, 2002). An overview of the application of JNT to space nuclear power and the current status of the ORNL JNT capabilities is the subject of this paper. C1 Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. RP Holcomb, DE (reprint author), Oak Ridge Natl Lab, Nucl Sci & Technol Div, Oak Ridge, TN 37831 USA. NR 10 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 567 EP 573 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600067 ER PT S AU Williams, RB AF Williams, RB BE ElGenk, MS TI Restricted complexity framework for nonlinear adaptive control in complex systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE ID AIRCRAFT AB Control law adaptation that includes implicit or explicit adaptive state estimation, can be a fundamental underpinning for the success of intelligent control in complex systems, particularly during subsystem failures, where vital system states and parameters can be impractical or impossible to measure directly. A practical algorithm is proposed for adaptive state filtering and control in nonlinear dynamic systems when the state equations are unknown or are too complex to model analytically. The state equations and inverse plant model are approximated by using neural networks. A framework for a neural network based nonlinear dynamic inversion control law is proposed, as an extrapolation of prior developed restricted complexity methodology used to formulate the adaptive state filter. Examples of adaptive filter performance are presented for an SSME simulation with high pressure turbine failure to support extrapolations to adaptive control problems. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Williams, RB (reprint author), Los Alamos Natl Lab, POB 1663,MS K575, Los Alamos, NM 87545 USA. NR 12 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 623 EP 630 PG 8 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600074 ER PT S AU Wood, RT Neal, JS Brittain, CR Mullens, JA AF Wood, RT Neal, JS Brittain, CR Mullens, JA BE ElGenk, MS TI Autonomous control capabilities for space reactor power systems SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB The National Aeronautics and Space Administration's (NASA's) Project Prometheus, the Nuclear Systems Program, is investigating a possible Jupiter Icy Moons Orbiter (JIMO) mission, which would conduct in-depth studies of three of the moons of Jupiter by using a space reactor power system (SRPS) to provide energy for propulsion and spacecraft power for more than a decade. Terrestrial nuclear power plants rely upon varying degrees of direct human control and interaction for operations and maintenance over a forty to sixty year lifetime. In contrast, an SRPS is intended to provide continuous, remote, unattended operation for up to fifteen years with no maintenance. Uncertainties, rare events, degradation, and communications delays with Earth are challenges that SRPS control must accommodate. Autonomous control is needed to address these challenges and optimize the reactor control design. In this paper, we describe an autonomous control concept for generic SRPS designs. The formulation of an autonomous control concept, which includes identification of high-level functional requirements and generation of a research and development plan for enabling technologies, is among the technical activities that are being conducted under the U.S. Department of Energy's Space Reactor Technology Program in support of the NASA's Project Prometheus. The findings from this program are intended to contribute to the successful realization of the JIMO mission. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wood, RT (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Neal, John/R-8203-2016 OI Neal, John/0000-0001-8337-5235 NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 631 EP 638 PG 8 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600075 ER PT S AU Houts, M Schmidt, GL Van Dyke, M Godfrey, T Martin, J Bragg-Sitton, S Dickens, R Salvail, P Harper, R AF Houts, M Schmidt, GL Van Dyke, M Godfrey, T Martin, J Bragg-Sitton, S Dickens, R Salvail, P Harper, R BE ElGenk, MS TI Space fission system test effectiveness SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB Space fission technology has the potential to enable rapid access to any point in the solar system. If fission propulsion systems are to be developed to their full potential, however, near-term customers need to be identified and initial fission systems successfully developed, launched, and utilized. One key to successful utilization is to develop reactor designs that are highly testable. Testable reactor designs have a much higher probability of being successfully converted from paper concepts to working space hardware than do designs which are difficult or impossible to realistically test. "Test Effectiveness" is one measure of the ability to realistically test a space reactor system. The objective of this paper is to discuss test effectiveness as applied to the design, development, flight qualification, and acceptance testing of space fission systems. The ability to perform highly effective testing would be particularly important to the success of any near-term mission, such as NASA's Jupiter Icy Moons Orbiter, the first mission under study within NASA's Project Prometheus, the Nuclear Systems Program. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, MS-K575, Los Alamos, NM 87545 USA. EM houts@lanl.gov NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 673 EP 679 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600079 ER PT S AU Ott, LYJ McCulloch, R AF Ott, LYJ McCulloch, R BE ElGenk, MS TI Overview of fuel rod simulator usage at ORNL SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB During the 1970s and early 1980s, the Oak Ridge National Laboratory (ORNL) operated large out-of-reactor experimental facilities to resolve thermal-hydraulic safety issues in nuclear reactors. The fundamental research ranged from material mechanical behavior of fuel cladding during the depressurization phase of a loss-of-coolant accident (LOCA) to basic heat transfer research in gas- or sodium-cooled cores. The largest facility simulated the initial phase (less than 1 min. of transient time) of a LOCA in a commercial pressurized-water reactor. The nonnuclear reactor cores of these facilities were mimicked via advanced, highly instrumented electric fuel rod simulators locally manufactured at ORNL. This paper provides an overview of these experimental facilities with an emphasis on the fuel rod simulators. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ott, LYJ (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 5 TC 3 Z9 3 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 703 EP 712 PG 10 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600083 ER PT S AU Ott, LJ McCulloch, R AF Ott, LJ McCulloch, R BE ElGenk, MS TI Electric fuel rod simulator fabrication at ORNL SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB Commercial vendors could not supply the high-quality, highly instrumented electric fuel rod simulators (FRS) required for large thermal-hydraulic safety-oriented experiments at the Oak Ridge National Laboratory (ORNL) in the 1970s and early 1980s. Staff at ORNL designed, developed, and manufactured the simulators utilized in these safety experiments. Important FRS design requirements include (1) materials of construction, (2) test power requirements and availability, (3) experimental test objectives, (4) supporting thermal analyses, and (5) extensive quality control throughout all phases of FRS fabrication. This paper will present an overview of these requirements (design, analytics, and quality control) as practiced at ORNL to produce a durable high-quality FRS. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ott, LJ (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 9 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 720 EP 727 PG 8 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600085 ER PT S AU Zinkle, SJ Wiffen, FW AF Zinkle, SJ Wiffen, FW BE ElGenk, MS TI Radiation effects in refractory alloys SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP Conference Proceedings LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE ID NEUTRON-IRRADIATED MOLYBDENUM; REACTOR STRUCTURAL-MATERIALS; FRACTURE-TOUGHNESS; MECHANICAL-PROPERTIES; TENSILE BEHAVIOR; TANTALUM; RHENIUM; METALS; STATE; TZM AB In order to achieve the required low reactor mass per unit electrical power for space reactors, refractory alloys are essential due to their high operating temperature capability that in turn enables high thermal conversion efficiencies. One of the key issues associated with refractory alloys is their performance in a neutron irradiation environment. The available radiation effects data are reviewed for alloys based on Mo, W, Re, Nb and Ta. The largest database is associated with Mo alloys, whereas Re, W and Ta alloys have the least available information. Particular attention is focused on Nb-1Zr, which is a proposed cladding and structural material for the reactor in the Jupiter Icy Moons Orbiter (JIMO) project. All of the refractory alloys exhibit qualitatively similar temperature-dependent behavior. At low temperatures up to similar to0.3T(M), where T-M is the melting temperature, the dominant effect of radiation is to produce pronounced radiation hardening and concomitant loss of ductility. The radiation hardening also causes a dramatic decrease in the fracture toughness of the refractory alloys. These low temperature radiation effects occur at relatively low damage levels of similar to0.1 displacement per atom, dpa (similar to2x10(24) n/m(2), E>0.1 MeV). As a consequence, operation at low temperatures in the presence of neutron irradiation must be avoided for all refractory alloys. At intermediate temperatures (0.3 to 0.6 T-M), void swelling and irradiation creep are the dominant effects of irradiation. The amount of volumetric swelling associated with void formation in refractory alloys is generally within engineering design limits (<5%) even for high neutron exposures (>>10 dpa). Very little experimental data exist on irradiation creep of refractory alloys, but data for other body centered cubic alloys suggest that the irradiation creep will produce negligible deformation for near-term space reactor applications. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. EM zinklesj@ornl.gov NR 48 TC 11 Z9 11 U1 2 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 733 EP 740 PG 8 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600087 ER PT S AU Goodwin, DP AF Goodwin, DP BE ElGenk, MS TI A propellantless propulsion experiment design and testing plan SO SPACE TECHNOLOGY AND APPLICATIONS INTERNATIONAL FORUM-STAIF 2004 SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Space Technology and Applications International Forum (STAIF 2004) CY FEB 08-11, 2004 CL Albuquerque, NM SP Boeing Co, Gen Autom, Lockheed Martin, Los Alamos Natl Lab, Northrop Grumman Space Technol, Sandia Natl Labs, US DOE AB A propellantless propulsion experiment design and testing plan are described. The concept was initially presented during the Space Technology and Applications International Forum of 2001 and the experiment was initially presented during the Joint Propulsion Conference of 2001. New information is provided on how the experiment relates to the Human Exploration of Development of Space, the results of peer reviews, a cost estimate performed by a major U.S. aerospace company, and an alternative magnet design to reduce the cost of the experiment and potentially improve the reliability of the system. Recent improvements in high power solid state switches and superconducting magnets may have made propellantless propulsion possible. Propulsion may occur during the non-steady state ramp-up of a very rapidly pulsed, high power magnet. Propulsion would not occur after the first 100 nanoseconds of each pulse, since the magnetic field will have reached steady state. The United States Department of Energy Office of High Energy Physics provided some of the funding for the developed a no maintenance superconducting magnet that can carry 2,000 amperes per square millimeter and a switch which can provide 100 nanosecond ramp-ups at a rate of 0.4 megahertz, and at 9,000 volts and 30 amperes. C1 US DOE, Off High Energy Phys, Washington, DC 20585 USA. RP Goodwin, DP (reprint author), US DOE, Off High Energy Phys, SC-20 Germantown Bldg,1000 Independence Ave SW, Washington, DC 20585 USA. NR 15 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0171-3 J9 AIP CONF PROC PY 2004 VL 699 BP 1175 EP 1181 PG 7 WC Engineering, Aerospace; Nuclear Science & Technology; Physics, Applied SC Engineering; Nuclear Science & Technology; Physics GA BY68D UT WOS:000189437600138 ER PT J AU Assefa, Z Haire, RG Raison, PE AF Assefa, Z Haire, RG Raison, PE TI Photoluminescence and Raman studies of Sm3+ and Nd3+ ions in zirconia matrices: example of energy transfer and host-guest interactions SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE photo-luminescence; energy-transfer; lanthanide; sensitized emission ID YTTRIA-STABILIZED ZIRCONIA; TEMPERATURE-DEPENDENCE; CUBIC ZIRCONIA; LUMINESCENCE; CRYSTALS; ZRO2; SPECTRA; DECAY; SPECTROSCOPY; FLUORESCENCE AB Photoluminescence and Raman studies on Sm3+- and Nd3+-doped zirconia are reported. The Raman studies indicate that the monoclinic (m) phase dominates up to a 10 at.% lanthanide level, while stabilization of the cubic phase is attained at similar to20 and similar to25 at.% of Sm3+ and Nd3+, respectively. Both systems are strongly luminescent under photo-excitation. The emission spectrum at 77 K of the ZrO2:Sm3+ system consists of a broad band at 505 nm, that corresponds to the zirconia matrix. At room temperature the band maximum blue-shifts to 490 nm. Sharper bands corresponding to f-f transitions within the Sm3+ ion are also exhibited in the longer wavelength region of the spectrum. Exclusive excitation of the zirconia matrix provides sensitized emission from the acceptor Sm3+ ion. The excitation profile is dominated by a broad band at 325 nm when monitored either at the zirconia or at one of the Sm3+ emissions. A spectral overlap between the H-6(5/2)-->(4)G(7/2) absorption of the Sm3+ ion with the zirconia emission leads to an efficient energy transfer process in the systems. Multiple facets of the spectral behavior of the Sm3+ or Nd3+ in the zirconia matrices, as well as the effects of compositions on the emission and Raman properties of the materials, and the role of defect centers in photoluminescence and the energy transfer processes are discussed. Published by Elsevier B.V. C1 Oak Ridge Natl Lab, Div Chem Sci, Oak Ridge, TN 37831 USA. Commiss European Communities, Inst Energy, Joint Res Ctr, NL-1755 ZG Petten, Netherlands. RP Assefa, Z (reprint author), Oak Ridge Natl Lab, Div Chem Sci, MS 6375, Oak Ridge, TN 37831 USA. NR 35 TC 42 Z9 43 U1 1 U2 19 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD JAN PY 2004 VL 60 IS 1-2 BP 89 EP 95 DI 10.1016/S1386-1425(03)00183-5 PG 7 WC Spectroscopy SC Spectroscopy GA 759RK UT WOS:000187750500010 PM 14670464 ER PT J AU Geipel, G Acker, M Vulpius, D Bernhard, G Nitsche, H Fanghanel, T AF Geipel, G Acker, M Vulpius, D Bernhard, G Nitsche, H Fanghanel, T TI An ultrafast time-resolved fluorescence spectroscopy system for metal ion complexation studies with organic ligands SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE time-resolved laser-excited fluorescence; uranium; carboxylic acid ID LASER-INDUCED FLUORESCENCE; PHOTOACOUSTIC-SPECTROSCOPY; HUMIC-ACID; URANIUM(VI); SPECIATION; CONSTANTS; STABILITY; TRLFS; UO22+ AB A dedicated spectrofluorimeter using ultrashort laser pulses as an excitation source was developed to measure the fluorescence properties of organic ligands for metal ion complexation with organic ligands. The laser system consists of an oscillator system for generation of femtosecond laser pulses. an amplifier system to increase the pulse energy of the generated pulses to about 2 mJ and an optical parametrical amplifier system to provide tunable laser pulses over a wide wavelength range (280 nm-10 mum). The laser pulses were applied to the sample and the emitted fluorescence was detected using a fast-gating intensified CCD camera-based spectrometer. To verify the performance of the laser, the well-known protonation constant [Pure Appl. Chem. 69 (1997) 329] of 2,3-dihydroxybenzoic acid was determined. The fluorescence lifetime of the excited species was determined as 375 32 ps in the pH range from 1.0 to 6.0, having a fluorescence emission maximum at 438 nm. The first protonation constant was determined from fluorescence data as log K-3 = 3.17 +/- 0.05 at an ionic strength of 0.1 M and at 294 K exploiting the Stern-Volmer mechanism. The agreement of the protonation constant with literature data (log K-3=3.10 +/- 0.20, I = 0.1 M, T=298 K [Bull. Soc. Jpn. 44 (1971) 3459]) demonstrates the excellent performance of our system. Furthermore, we determined the complex formation constant log K-1 = -3.11 +/- 0.16 by measuring the fluorescence properties of the ligand for the 1:1 uranyldihydroxobenzoate complex in the pH range from 3.0 to 4.5 at ionic strength of 0.1 M and at 294 K. We also determined the complex formation constant via the fluorescence emission of the metal ion uranium(VI). The fluorescence of the uranyl ion is influenced by dynamic quenching of the non-dissociated ligand and by static quenching due to the complex formation. After correction of these effects using the determined fluorescence lifetime, the complex formation constant was calculated to be log K-1 = -3.99 +/- 0.44. A 1:1 metal:ligand stoichiometry was determined with both measurement methods. However, the difference of the obtained formation constants and the derived standard deviations indicate a superimposition of effects with the excited-state reactions of the ligand. (C) 2003 Elsevier B.V. All rights reserved. C1 Rossendorf Inc, Forschungszentrum Rossendorf EV, Inst Radiochem, D-01314 Dresden, Germany. Tech Univ Dresden, Inst Luft & Raumfahrttechn, D-01062 Dresden, Germany. Univ Calif Berkeley, Div Nucl Sci, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. Forschungszentrum Karlsruhe, Inst Nukl Entsorgung, D-76021 Karlsruhe, Germany. RP Geipel, G (reprint author), Rossendorf Inc, Forschungszentrum Rossendorf EV, Inst Radiochem, POB 510119, D-01314 Dresden, Germany. NR 27 TC 22 Z9 22 U1 2 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD JAN PY 2004 VL 60 IS 1-2 BP 417 EP 424 DI 10.1016/S1386-1425(03)00244-0 PG 8 WC Spectroscopy SC Spectroscopy GA 759RK UT WOS:000187750500054 PM 14670508 ER PT J AU Thomas, JJ Bothner, B Traina, J Benner, WH Siuzdak, G AF Thomas, JJ Bothner, B Traina, J Benner, WH Siuzdak, G TI Electrospray ion mobility spectrometry of intact viruses SO SPECTROSCOPY-AN INTERNATIONAL JOURNAL LA English DT Article ID FLIGHT MASS-SPECTROMETRY; COWPEA MOSAIC-VIRUS; GASEOUS PROTEIN IONS; PLASMA CHROMATOGRAPHY; RNA; RESOLUTION; STABILITY; BINDING AB Characterizing supramolecular interactions offers significant challenges using NMR or crystallographic techniques either because of size limitations or the difficulty in forming suitable crystals, while mass spectrometry is largely limited to low resolution mass information. Here we report gas phase measurements of intact virus particles using electrospray ion mobility spectrometry with an accuracy in radial measurements that were sufficient to differentiate closely related species. In addition, measured diameters indicate that iscosahedral virus particles retain their structure in the gas phase as well as undergoing a slight compaction in the absence of solvent. Analysis of the human pathogen adenovirus represents the largest and most sophisticated biomolecular complex detected in the gas phase to date. These results, on a diverse set of viral systems, suggest that ion mobility spectrometry may have broad applications for the analysis of biological complexes. C1 Scripps Res Inst, Ctr Mass Spectrometry, La Jolla, CA 92037 USA. Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Berlex Biosci, Richmond, CA 94806 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Siuzdak, G (reprint author), Scripps Res Inst, Ctr Mass Spectrometry, 10550 N Torrey Pines Rd, La Jolla, CA 92037 USA. EM siuzdak@scripps.edu NR 29 TC 60 Z9 61 U1 0 U2 20 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0712-4813 J9 SPECTROSC-INT J JI Spectr.-Int. J. PY 2004 VL 18 IS 1 BP 31 EP 36 PG 6 WC Biochemical Research Methods; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 768LP UT WOS:000188544700003 ER PT J AU Scott, JR Ham, JE Durham, B Tremblay, PL AF Scott, JR Ham, JE Durham, B Tremblay, PL TI Ruthenium trisbipyridine as a candidate for gas-phase spectroscopic studies in a Fourier transform mass spectrometer SO SPECTROSCOPY-AN INTERNATIONAL JOURNAL LA English DT Article; Proceedings Paper CT 2nd International Conference on Biomedical Spectroscopy CY JUL 05-08, 2003 CL London, ENGLAND ID ION-CYCLOTRON RESONANCE; INTRAMOLECULAR ELECTRON-TRANSFER; LASER-INDUCED FLUORESCENCE; POLYPYRIDINE COMPLEXES; CYTOCHROME B(5); TRAPPED IONS; REORGANIZATIONAL ENERGY; FLASH-PHOTOLYSIS; DESORPTION; RESOLUTION AB Metal polypyridines are excellent candidates for gas-phase optical experiments where their intrinsic properties can be studied without complications due to the presence of solvent. The fluorescence lifetimes of [Ru(bpy)(3)](1+) trapped in an optical detection cell within a Fourier transform mass spectrometer were obtained using matrix-assisted laser desorption/ionization to generate the ions with either 2,5-dihydroxybenzoic acid (DHB) or sinapinic acid (SA) as matrix. All transients acquired, whether using DHB or SA for ion generation, were best described as approximately exponential decays. The rate constant for transients derived using DHB as matrix was 4 x 10(7) s(-1), while the rate constant using SA was 1 x 10(7) s(-1). Some suggestions of multiple exponential decay were evident although limited by the quality of the signals. Photodissociation experiments revealed that [Ru(bpy)(3)](1+) generated using DHB can decompose to [Ru(bpy)(2)](1+), whereas ions generated using SA showed no decomposition. Comparison of the mass spectra with the fluorescence lifetimes illustrates the promise of incorporating optical detection with trapped ion mass spectrometry techniques. C1 INEEL, Idaho Falls, ID 83415 USA. Univ Arkansas, Dept Chem & Biochem, Fayetteville, AR 72701 USA. RP Scott, JR (reprint author), INEEL, 2525 N Fremont Ave,MS 2208, Idaho Falls, ID 83415 USA. EM scotjr@inel.gov RI Scott, Jill/G-7275-2012 NR 34 TC 7 Z9 7 U1 0 U2 2 PU IOS PRESS PI AMSTERDAM PA NIEUWE HEMWEG 6B, 1013 BG AMSTERDAM, NETHERLANDS SN 0712-4813 J9 SPECTROSC-INT J JI Spectr.-Int. J. PY 2004 VL 18 IS 2 SI SI BP 387 EP 396 PG 10 WC Biochemical Research Methods; Spectroscopy SC Biochemistry & Molecular Biology; Spectroscopy GA 827AE UT WOS:000221869800029 ER PT B AU Perry, DL Bowman, A Teat, SJ Ortega, M Thompson, AC AF Perry, DL Bowman, A Teat, SJ Ortega, M Thompson, AC BE Faulques, EC Perry, DL Yeremenko, AV TI Structural studies iof bio- and realted materials using synchrotron radiation: The structure of tetra(imidazole)chlorocopper(II) chloride. SO SPECTROSCOPY OF EMERGING MATERIALS SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Frontiers in Spectroscopy of Emergent Materials CY SEP 14-18, 2003 CL Sudak, UKRAINE DE imidazole; copper(II); nanochemistry; nanoparticles; tetra(imidazole)chlorocopper(II) chloride; synchrotron; x-ray crystallography; biomaterials; [Cu(imidazole)(4)Cl]Cl ID IMIDAZOLE COMPLEXES AB The complex tetra(imidazole)chlorocopper(II) chloride, [Cu(imidazole)(4)Cl]Cl, has been synthesized, and the structure has been determined at the Small Crystal X-ray Crystallography Beamline (11.3.1) of the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL), USA. Structural parameters of the parent complex are compared to similar materials previously reported in the literature. The particles in the present study can be used to prepare nanoparticle materials, or, by controlled growth, can be formed as nanoparticles initially. The structural data are important for making detailed calculations, models, and deriving reaction mechanisms involving metal ion-based biochemical systems. C1 Lawrence Berkeley Natl Univ, Berkeley, CA 94720 USA. RP Perry, DL (reprint author), Lawrence Berkeley Natl Univ, Berkeley, CA 94720 USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-2395-2 J9 NATO SCI SER II MATH PY 2004 VL 165 BP 31 EP 43 PG 13 WC Materials Science, Characterization & Testing; Spectroscopy SC Materials Science; Spectroscopy GA BBB05 UT WOS:000224462500003 ER PT B AU Shvartsburg, AA Horoi, M Jackson, KA AF Shvartsburg, AA Horoi, M Jackson, KA BE Faulques, EC Perry, DL Yeremenko, AV TI Growth of silicon nanclusters - Elucidation by gas phase experiments and DFT calculations SO SPECTROSCOPY OF EMERGING MATERIALS SE NATO SCIENCE SERIES, SERIES II: MATHEMATICS, PHYSICS AND CHEMISTRY LA English DT Proceedings Paper CT NATO Advanced Research Workshop on Frontiers in Spectroscopy of Emergent Materials CY SEP 14-18, 2003 CL Sudak, UKRAINE DE clusters; ion mobility spectrometry; photoelectron spectroscopy; collision-induced dissociation; molecular structure optimization ID ION MOBILITY MEASUREMENTS; COLLISION-INDUCED DISSOCIATION; CLUSTER IONS; SEMICONDUCTOR CLUSTERS; TIGHT-BINDING; SI CLUSTERS; STRUCTURAL INFORMATION; FINITE-TEMPERATURE; DENSITY; EQUILIBRIUM AB Semiconductor nanostructures are of great interest from both fundamental and applied perspectives. They are intriguing scientifically because their bonding and properties deviate strongly from those of their bulk solids and relevant industrially since nanodevices now approach the scale of large clusters. Understanding the behavior of any molecular system starts from ascertaining its structure. So a colossal effort was expended over the last two decades on characterizing semiconductor cluster geometries. As silicon is the most critical semiconductor, that effort largely focused on Si clusters. Structures of small Si clusters were elucidated early on by ab initio calculations, vibrationally resolved spectroscopy, and optical spectroscopies of matrix-isolated species. Progress for larger systems was enabled in late 1990s by an integrated suite of new tools. It includes ion mobility spectrometry, photoelectron spectroscopy, collisional dissociation, and threshold ionization on the side of experiment, and novel molecular optimization algorithms based on evolution paradigm and fast, but accurate semiempirical protocols for energy evaluation on the theory side. Coherent application of these methods has characterized Si clusters up to the region of radical transition from prolate to spherical growth at similar to25 atoms. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Shvartsburg, AA (reprint author), Pacific NW Natl Lab, MS K8-98,3335 Q Ave, Richland, WA 99352 USA. NR 46 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 1-4020-2395-2 J9 NATO SCI SER II MATH PY 2004 VL 165 BP 83 EP 96 PG 14 WC Materials Science, Characterization & Testing; Spectroscopy SC Materials Science; Spectroscopy GA BBB05 UT WOS:000224462500007 ER PT B AU Colgate, SA AF Colgate, SA BE Johnstone, D Adams, FC Lin, DNC Neufeld, DA Ostriker, EC TI Star formation and cosmic massive black hole formation, a universal process organized by angular momenta SO STAR FORMATION IN THE INTERSTELLAR MEDIUM: IN HONOR OF DAVID HOLLENBACH, CHRIS MCKEE AND FRANK SHU SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT Conference on Star Formation in the Interstellar Medium held in honor of David Hollenbach, Chris McKee and Frank Shu CY JUN 30-JUL 03, 2003 CL Lake Tahoe, CA ID GALAXIES; ORIGIN; MODES AB It is suggested that star formation is organized following the same principles as we have applied in a recent explanation of galaxy and massive black hole formation. In this scenario angular momentum is randomly distributed by tidal torquing among condensations, Lyman-alpha clouds or cores for star formation during the initial non-linear phase of collapse. This angular momentum is characterized by the parameter, lambda, the ratio of the angular momentum of the cloud to that of a Keplerian orbit with the same central mass and radius. This parameter is calculated in very many simulations of structure formation of the universe as well as core formation and appears to be universal and independent of any scale. The specific angular momentum during the collapse of every cloud is locally conserved and universally produces a near flat rotation curve M- monochromator and a toroidal mirror are inside the synchrotron shield wall only 7m from the bending magnet source point. The monochromator is cooled with a small Joule-Thomson refrigerator to produce a very small beam motion with different heat loads. The experimental hutch contains a vertically mounted sample goniometer and a CCD detector. An on-axis visual alignment camera allows the small crystals to be accurately centered within the x-ray beam. Examples of the crystal structures solved with this system are given. The beamline is also used for high-pressure powder diffraction experiments using a diamond anvil cell that is mounted on a stage system that can be quickly installed and removed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Thompson, AC (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 2 TC 4 Z9 4 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 482 EP 485 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000119 ER PT S AU Trame, C MacDowell, AA Celestre, RS Padmore, HA Cambie, D Domning, EE Duarte, RM Kelez, N Plate, DW Holton, JM Frankel, K Tsutakawa, S Tsuruta, H Tainer, JA Cooper, PK AF Trame, C MacDowell, AA Celestre, RS Padmore, HA Cambie, D Domning, EE Duarte, RM Kelez, N Plate, DW Holton, JM Frankel, K Tsutakawa, S Tsuruta, H Tainer, JA Cooper, PK BE Warwick, T Arthur, J Padmore, HA Stohr, J TI SIBYLS - a SAXS and protein crystallography beamline at the ALS SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB The new Structurally Integrated BiologY for Life Sciences (SIBYLS) beamline at the Advanced Light Source will be dedicated to Macromolecular Crystallography (PX) and Small Angle X-ray Scattering (SAXS). SAXS will provide structural information of macromolecules in solutions and will complement high resolution PX studies on the same systems but in a crystalline state. The x-ray source is one of the 5 Testa superbend dipoles recently installed at the ALS that allows for a hard x-ray program to be developed on the relatively low energy Advanced Light Source (ALS) ring (1.9 GeV). The beamline is equipped with fast interchangeable monochromator elements, consisting of either a pair of single Si(111) crystals for crystallography, or a pair of multilayers for the SAXS mode data collection (E/DeltaEsimilar to1/110). Flux rates with Si(111) crystals for PX are measured as 2x10(11) hv/sec through a 100mum pinhole at 12.4KeV. For SAXS the flux is up to 3x10(13) photons/sec at 10KeV with all apertures open when using the multilayer monochromator elements. The performance characteristics of this unique beamline will be described. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Trame, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI MacDowell, Alastair/K-4211-2012 NR 5 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 502 EP 505 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000124 ER PT S AU Scarvie, T Andresen, N Baptiste, K Byrd, J Chin, M Martin, M McKinney, W Steier, C AF Scarvie, T Andresen, N Baptiste, K Byrd, J Chin, M Martin, M McKinney, W Steier, C BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Noise reduction efforts for the ALS infrared beamlines SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID ADVANCED LIGHT-SOURCE AB The quality of infrared microscopy and spectroscopy data collected at synchrotron based sources is strongly dependent on signal-to-noise. We have successfully identified and suppressed several noise sources affecting Beamlines 1.4.2, 1.4.3, and 1.4.4 at the Advanced Light Source (ALS), resulting in a significant increase in the quality of FTIR spectra obtained. In this paper, we present our methods of noise source analysis, the negative effect of noise on the infrared beam quality, and the techniques used to reduce the noise. These include reducing the phase noise in the storage ring radio-frequency (RF) system, installing an active mirror feedback system, analyzing, and changing physical mounts to better isolate portions of the beamline optics from low-frequency environmental noise, and modifying the input signals to the main ALS RF system. We also discuss the relationship between electron beam energy oscillations at a point of dispersion and infrared beamline noise. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source Div, Berkeley, CA 94720 USA. RP Scarvie, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source Div, Berkeley, CA 94720 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 541 EP 544 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000133 ER PT S AU Lazarski, K Alkire, RW Duke, NEC Rotella, FJ AF Lazarski, K Alkire, RW Duke, NEC Rotella, FJ BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Software controls for automated feedback tuning SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB The Structural Biology Center (SBC) beamlines have been designed to take full advantage of the highly intense radiation available at Argonne's Advance Photon Source for crystallography experiments. In order to facilitate the delivery of an intense, stable x-ray beam to crystallographic samples, new beam position stabilization software has been developed. Using the beam-position monitor developed by Alkire, Rosenbaum and Evans, the position of the beam is corrected in real time by applying changes to the monochromator tune using DC servomotors. Real-time monitoring tools were developed, in addition to the technique of selecting the reference trigger points. A user interface for feedback tuning has been developed in conjunction with real-time monitoring and interacting with data acquisition at the bending-magnet beamline (19BM) of the SBC. Preliminary results showed positional stability of the beam to better than 1 murad in tune. C1 Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. RP Lazarski, K (reprint author), Argonne Natl Lab, Biosci Div, Struct Biol Ctr, Argonne, IL 60439 USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 612 EP 615 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000151 ER PT S AU Qian, SN Takacs, P Dong, QL Hulbert, S AF Qian, SN Takacs, P Dong, QL Hulbert, S BE Warwick, T Arthur, J Padmore, HA Stohr, J TI In-situ precise angle monitoring on synchrotron radiation monochromator by use of pencil beam interferometer SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID LONG TRACE PROFILER; HEAT-LOAD MIRROR AB Monochromator is a very important and precise instrument used in beam lines at synchrotron radiation facilities. We need to know if there is actual thermal distortion on gratings resulting in the degradation of the monochromator resolution. We need to know the characteristics of the grating rotation. It is possible to make a simple but precise in-situ distortion monitoring and rotation angle test of the grating by use of a precise pencil beam angle monitor. We have made preliminary measurements on a monochrometer grating of an undulator beam line X1B at Brookhaven National Laboratory. We monitored a small amount of angle variation on the grating. We detected 1.7 murad backlash (PV) of the grating controlling system. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Qian, SN (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. NR 7 TC 2 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 616 EP 619 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000152 ER PT S AU Caliebe, WA Cheung, S Lenhard, A Siddons, DP AF Caliebe, WA Cheung, S Lenhard, A Siddons, DP BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Fixed exit monochromator with fixed rotation axis SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID RAY SYNCHROTRON-RADIATION; CRYSTAL AB A new simple design for a fixed-exit monochromator has been developed. The set-up uses a linear slide to couple the rotation of the crystals to a translation of the second one to compensate for the 2hcosTheta dependence of the beam-offset in a double crystal monochromator. This set-up requires just one motor for the rotation of the monochromator, and three piezo-actuators to tune the second crystal. The monochromator has been tested for Bragg-angles between 7degrees and 70degrees. C1 Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Caliebe, WA (reprint author), Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. NR 11 TC 1 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 643 EP 646 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000158 ER PT S AU Beno, MA Rutt, U Kurtz, C Jennings, G AF Beno, MA Rutt, U Kurtz, C Jennings, G BE Warwick, T Arthur, J Padmore, HA Stohr, J TI High-energy Bragg and Laue monochromators for an APS Wiggler beamline SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID TRIPLE-CRYSTAL DIFFRACTOMETER; SYNCHROTRON-RADIATION; SCATTERING AB The elliptical multipole wiggler located at Sector 11 of the Advanced Photon Source has a maximum critical energy of 32 keV and a total power output of similar to 8 kW. The device produces circularly polarized X-rays on-axis and linearly polarized X-rays above and below the ring plane. A double crystal monochromator intercepts the lower linearly polarized radiation to be used in the 11ID-D experimental station for scattering and spectroscopy experiments in the 5 to 40 keV energy range. The on-axis circularly polarized photons and upper linearly polarized photons are monochromatized by one crystal horizontally deflecting monochromators at fixed Bragg angles of theta = 3.8degrees and theta = 1.9degrees respectively. We will present here the designs and detail the performance of Laue and Bragg monochromator designs for these two beamlines which operate at fixed energies from similar to60 keV to 125 keV. For the high-energy diffraction station, 11ID-C, which utilizes the upper linearly polarized radiation, the Laue monochromator design allows rapid interchange of crystals and provides a photon flux of 2 x 10(12) photons/sec in a 2.5 x 3.5 mm spot at 98 keV using annealed Silicon crystals (Si(220)). The Bragg monochromator design provides focusing and a smaller bandwidth while retaining a high photon flux. The high heatloads generated by the EMPW present design challenges for both monochromator designs. C1 Argonne Natl Lab, Adv Photon Source, Expt Facilities Div, Argonne, IL 60439 USA. RP Beno, MA (reprint author), Argonne Natl Lab, Adv Photon Source, Expt Facilities Div, Argonne, IL 60439 USA. RI Kurtz, Chalres/G-1037-2011 OI Kurtz, Chalres/0000-0003-2606-0864 NR 7 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 675 EP 678 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000166 ER PT S AU Liu, C Conley, R Assoufid, L Cai, Z Qian, J Macrander, AT AF Liu, C Conley, R Assoufid, L Cai, Z Qian, J Macrander, AT BE Warwick, T Arthur, J Padmore, HA Stohr, J TI From flat substrate to elliptical KB mirror by profile coating SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID ESRF AB For microfocusing x-ray mirrors, an elliptical shape is essential for aberration-free optics. However, it is difficult to polish elliptical mirrors to x-ray-quality smoothness. Profile coatings have been applied on both cylindrical and flat Si substrates to make the desired elliptical shape. In a profile-coating process, the sputter source power is kept constant, while the substrate is passed over a contoured mask at a constant speed to obtain a desired profile along the direction perpendicular to the substrate-moving direction. The shape of the contour was derived from a desired profile and the thickness distribution of the coating material at the substrate level. The thickness distribution was measured on films coated on Si wafers using a spectroscopic ellipsometer with computer-controlled X-Y translation stages. The mirror coating profile is determined from the difference between the ideal surface figure of a focusing ellipse and the surface figure obtained from a long trace profiler measurement on the substrate. The number of passes and the moving speed of the substrate are determined according to the required thickness and the growth-rate calibration of a test run. A KB mirror pair was made using Au as a coating material and cylindrically polished mirrors as substrates. Synchrotron x-ray results using this KB mirror pair showed a focused spot size of 0.4 x 0.4 mum(2). This technique has also been applied for making elliptical KB mirrors from flat Si substrates. The challenges and solutions associated with elliptical profile coating on flat substrates will be discussed. C1 Argonne Natl Lab, Expt Facilities Div, Argonne, IL 60439 USA. RP Liu, C (reprint author), Argonne Natl Lab, Expt Facilities Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Conley, Ray/C-2622-2013 NR 12 TC 11 Z9 11 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 704 EP 707 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000173 ER PT S AU Smither, RK Khounsary, AM Mancini, DC Abu Saleem, K AF Smither, RK Khounsary, AM Mancini, DC Abu Saleem, K BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Performance of a Be refractive lens SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB The performance of a beryllium compound refractive lens (CRL) was tested in the energy range of 11.5 to 8.0 keV. The beryllium refractive lens consists of 50 aligned, 1-mm-diameter, hollow spheres in a solid block of beryllium, 30 mm x 20 mm x 55 mm. The minimum web between each hollow sphere was 0.10 mm. The measured focal length of the lens for x-rays close to the axis of the beam was 147.7 cm +/- 2.0 cm at 10 keV and 120.2 +/- 2.0 cm at 9.1 keV. These values agree well with the theoretical values of 146.6 cm and 121.4 cm, respectively. The diameter of the best focus obtained at 10 keV was 35 mum horizontal and 45 pm vertical. For the modified version of the lens used in the 9.1 keV experiment these values were 25 Pin horizontal and 35 mum vertical. The x-ray beam cross section for the 10 keV and the 9.1 keV experiments were 0.50 mm x 0.50 mm and 0.30 mm x 0.30 mm, respectively. The enhancement of the flux (photons per sq. mm) was 50:1 at 10 keV and 80:1 in the 9.1 keV experiment. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Smither, RK (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 716 EP 719 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000176 ER PT S AU Warwick, T Andresen, N Comins, J Franck, A Gilles, M Tonnessen, T Tyliszczak, T AF Warwick, T Andresen, N Comins, J Franck, A Gilles, M Tonnessen, T Tyliszczak, T BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Large aperture micro-focus KB mirrors for spectroscopy experiments at the advanced light source SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB General purpose refocus mirrors using Kirkpatrick-Baez geometry have been designed, built and installed at a new undulator beam-line facility to provide spot sizes smaller than 10 microns for specialized spectroscopy experiments at the Advanced Light Source. All the available flux is focused and the focal length is adjustable. The mirrors are fully computer controlled and can be detuned to create a spot as big as 500 microns. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Warwick, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 772 EP 775 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000190 ER PT S AU Xu, S Fischetti, RF AF Xu, S Fischetti, RF BE Warwick, T Arthur, J Padmore, HA Stohr, J TI A ray-tracing study of the dependence of focal properties on surface figure error for a Kirkpatrick-Baez (K-B) mirror system SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB In the last several years, Kirkpatrick-Baez (K-B) mirror systems have been extensively applied as two-dimensional x-ray focusing elements on x-ray beamlines at low emittance, third generation, synchrotron radiation facilities. The design of the two GM/CA CAT insertion device beamlines at the Advanced Photon Source at Argonne National Laboratory for macromolecular crystallography includes a K-B mirror system situated in each of the experimental stations. Ray-tracing studies have been performed using SHADOW (V2.3.2) to investigate the dependence of the focal distance on the surface figure error obtained from LTP metrology measurements. Additionally, a procedure has been developed to allow one to change the mirror focal positions to provide a beam of given dimensions at a fixed position before or after the focal position. The GM/CA CAT has been established by the National Institutes of Health's (NIH) National Institute of General Medical Sciences (NIGMS), and the National Cancer Institute (NCI) to build and operate a national user facility for crystallographic structure determination of biological macromolecules by X-ray diffraction. C1 Argonne Natl Lab, Biosci Div, GM CA CAT, Argonne, IL 60439 USA. RP Xu, S (reprint author), Argonne Natl Lab, Biosci Div, GM CA CAT, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 776 EP 779 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000191 ER PT S AU Naulleau, PP Goldberg, KA Batson, P Denham, P Rekawa, S AF Naulleau, PP Goldberg, KA Batson, P Denham, P Rekawa, S BE Warwick, T Arthur, J Padmore, HA Stohr, J TI A synchrotron-based Fourier-synthesis custom-coherence illuminator SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID EXTREME-ULTRAVIOLET LITHOGRAPHY; LIGHT-SOURCE; SYSTEM AB Scanning illumination systems provide for a powerful and flexible means for controlling illumination coherence properties. Here we present a synchrotron-based scanning-mirror Fourier synthesis illuminator that enables sources with intrinsically high spatial coherence, such as undulators, to be used in situations demanding less coherence. The application considered here involves microfield extreme ultraviolet (EUV) lithography, however, the same methods are applicable to conventional microscopy as well as coherence-imaging techniques. This flexible illuminator allows the coherence to be tuned in situ enabling the illumination to be tailored to the specific pattern being imaged. The effectiveness of the system is demonstrated through a variety of lithographic print experiments. These include the use of resolution enhancing coherence functions, which enable the printing of 50-nm line-space features using a lithographic optic with a NA of 0.1 and an operational wavelength of 13.4 nm. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Naulleau, PP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 792 EP 795 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000195 ER PT S AU Alkire, RW Duke, NEC Rotella, FJ AF Alkire, RW Duke, NEC Rotella, FJ BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Setting the twist of a sagittally bent crystal using a beam position monitor SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB Implementation of a monolithic, unribbed, sagittally bent focusing crystal on a bending magnet source has proven to be quite challenging. Ultimate performance depends upon the quality of the focusing crystal, how well the bender works and on the number of degrees of freedom available for adjustment. Here we report on progress toward optimizing focusing crystal performance by examining the effects of twist as they relate to beam position. All work was performed at beamline 19BM at the Advanced Photon Source. C1 Argonne Natl Lab, Struct Biol Ctr, Biosci Div, Argonne, IL 60439 USA. RP Alkire, RW (reprint author), Argonne Natl Lab, Struct Biol Ctr, Biosci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 827 EP 830 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000203 ER PT S AU Takacs, PZ Qian, SN AF Takacs, PZ Qian, SN BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Accuracy limitations in long-trace profilometry SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB As requirements for surface slope error quality of grazing incidence optics approach the 100 nanoradian level, it is necessary to improve the performance of the measuring instruments to achieve accurate and repeatable results at this level, We have identified a number of internal error sources in the Long Trace Profiler (LTP) that affect measurement quality at this level. The LTP is sensitive to phase shifts produced within the millimeter diameter of the pencil beam probe by optical path irregularities with scale lengths of a fraction of a millimeter. We examine the effects of mirror surface "macroroughness" and internal glass homogeneity on the accuracy of the LTP through experiment and theoretical modeling. We will place limits on the allowable surface "macroroughness" and glass homogeneity required to achieve accurate measurements in the nanoradian range. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Takacs, PZ (reprint author), Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. NR 2 TC 8 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 831 EP 834 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000204 ER PT S AU Assoufid, L Bray, M Shu, DM AF Assoufid, L Bray, M Shu, DM BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Development of a linear stitching interferometric system for evaluation of very large x-ray synchrotron radiation substrates and mirrors SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB Stitching interferometry, using small-aperture, high-resolution, phase-measuring interferometric systems has been investigated for quite some time now as a metrology technique to obtain surface profiles of oversized optical components and substrates. The technique offers the potential for providing 3D measurements of mirror surfaces with nanometer resolution. The aim of this work is to apply this technique to the specific case of large, flat, grazing-incidence x-ray mirrors, such as those used in beamlines at synchrotron radiation facilities around the world. In the case of x-ray mirrors, obtaining a 3D surface profile can be particularly useful in many instances, for example, in selecting the best reflecting stripe on a mirror surface to be used for undulator beams. The measurement data can be used for simulating and predicting mirror performance under realistic conditions, etc. A fully automated stitching system is currently being developed at the metrology laboratory of the Advanced Photon Source at Argonne National Laboratory. Preliminary tests performed on a 460-mm-long flat float-glass substrate and on a 300-mm-long superpolished silicon substrate, were encouraging. The stitched profiles showed no obvious overlap errors, and the results agree well with those obtained using other techniques. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Assoufid, L (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 851 EP 854 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000209 ER PT S AU Goldberg, KA Naulleau, P Rekawa, S Denham, P Liddle, JA Anderson, E Jackson, K Bokor, J Attwood, D AF Goldberg, KA Naulleau, P Rekawa, S Denham, P Liddle, JA Anderson, E Jackson, K Bokor, J Attwood, D BE Warwick, T Arthur, J Padmore, HA Stohr, J TI At-wavelength interferometry of high-NA diffraction-limited EUV optics SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID LATERAL SHEARING INTERFEROGRAMS; FOURIER-TRANSFORM; X-RAY; SYSTEM; ALIGNMENT AB Recent advances in all-reflective diffraction-limited optical systems designed for extreme ultraviolet (EUV) lithography have pushed numerical aperture (NA) values from 0.1 to 0.3, providing Rayleigh resolutions of 27-nm. Worldwide, several high-NA EUV optics are being deployed to serve in the development of advanced lithographic techniques required for EUV lithography, including the creation and testing of new, high-resolution photoresists. One such system is installed on an undulator beamline at Lawrence Berkeley National Laboratory's Advanced Light Source. SubAngstrom-accuracy optical testing and alignment techniques, developed for use with the previous generations of EUV lithographic optical systems, are being extended for use at high NA. Considerations for interferometer design and use are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Goldberg, KA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RI Liddle, James/A-4867-2013 OI Liddle, James/0000-0002-2508-7910 NR 21 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 855 EP 858 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000210 ER PT S AU McKinney, WR AF McKinney, WR BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Design of emission spectrometers with resolving power of 10,000 SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB A systematic design procedure is outlined which allows the achievement of maximum resolving power of a grating spectrometer for soft X-ray emission. Starting with a finite overall size the source size limit is balanced against the detector limited resolving power to find the optimal distance between entrance slit or image, focusing mirror, varied line space grating, and detector. An example is given showing ray traces of an instrument of 2.5 meter overall size and a resolving power of 10,000. A tangential elliptical mirror permits an optimal design to be achieved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP McKinney, WR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 877 EP 880 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000215 ER PT S AU Caliebe, WA Qian, Q Tyson, TA Deyhim, A Blank, B Kao, CC AF Caliebe, WA Qian, Q Tyson, TA Deyhim, A Blank, B Kao, CC BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Multi-element analyzer for inelastic x-ray scattering SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID BENT PERFECT CRYSTALS; REFLECTIVITY; SPECTROSCOPY AB A nine-element analyzer-system for inelastic x-ray scattering has been designed and built. Each individual analyzer crystal is aligned with an inverse joy-stick goniometer. The energy of the scattered photons is measured with a conventional double-circle goniometer mounted on a translation stage, which allows the maintenance of the sample, analyzers and detector, also mounted on a separate translation stage, on a Rowland-circle. C1 Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Caliebe, WA (reprint author), Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. NR 18 TC 1 Z9 1 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 893 EP 896 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000219 ER PT S AU Ito, K Gaponov, Y Sakabe, N Amemiya, Y AF Ito, K Gaponov, Y Sakabe, N Amemiya, Y BE Warwick, T Arthur, J Padmore, HA Stohr, J TI A 100 % duty-ratio 3 x 6 arrayed CCD x-ray detector for rapid data collection in macromolecular crystallography SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB A 3 x 6 arrayed charge coupled device (CCD) X-ray detector has been developed for rapid data collection in macromolecular crystallography at Photon Factory. The total active area is 236 mm x 236 mm (76.8 mum x 76.8 mum/ pixel at the input phosphor, 3072 x 3072 pixels). Each module consists of an input phosphor, a 3.2:1 fiber-optic-taper (FOT), a CCD, and a readout circuit. The input phosphor is Gd2O2S:Tb (P-43), which is deposited onto an aluminum coated Mylar sheet to increase the sensitivity. The outputs from eighteen (3 x 6) CCDs are readout in parallel and then are digitized by 16 bit analog-to-digital converters. The advantage of this detector over the conventional FOT-coupled CCD detectors is a unique CCD readout scheme that enables us to record successive x-ray exposures without interruption among them. A shutter is not needed for CCD readout and the sample crystal can be rotated continuously without interruption during data acquisition. We have collected one data set of a Lysozyme crystal for 180 degree with 1.5 degree per slice in 360 seconds. The exposure time of each slice is 3 seconds. The duty-ratio of the x-ray exposure to the data collection time is 100%. This detector combined with a synchrotron radiation source is very suitable for rapid data collection in macromolecular crystallography. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Amemiya, Y (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd,Bldg 274 MS 99, Menlo Pk, CA 94025 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 913 EP 916 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000224 ER PT S AU Siddons, DP Zhong, Z AF Siddons, DP Zhong, Z CA SPPS Collaboration BE Warwick, T Arthur, J Padmore, HA Stohr, J TI A flash spectrograph for XANES measurements at SPPS/LCLS SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB The SPPS and LCLS are next-generation light sources which will produce ultra-short x-ray pulses a few 10's of femtoseconds long, with large numbers of photons per pulse. These sources will enable new types of x-ray experiments, but will require new approaches to optical instruments. We present here a spectrograph tailored for use with such sources, allowing the small beam cross-section to be spatially dispersed by means of a curved asymmetric Brag reflecting crystal. The design allows for an adjustable energy range by changing the radius of curvature within certain limits. Although inspired by these new sources, the device is also well adapted to conventional synchrotron radiation beamlines. It is significantly more compact than conventional wavelength-dispersive devices, and has resolution advantages. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Siddons, DP (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. NR 1 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 941 EP 944 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000231 ER PT S AU Bussat, JM Fadley, CS Hussain, Z Kay, AW Lebedev, G Ludewigt, BA Meddeler, G Nambu, A Press, M Spieler, H Turko, B West, M Zizka, G AF Bussat, JM Fadley, CS Hussain, Z Kay, AW Lebedev, G Ludewigt, BA Meddeler, G Nambu, A Press, M Spieler, H Turko, B West, M Zizka, G BE Warwick, T Arthur, J Padmore, HA Stohr, J TI An ultra-high-speed detector for synchrotron radiation research SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB An ultra high-speed, one-dimensional multi-channel detector for electrons and soft x-ray photons has been developed to permit full utilization of fluxes from third- and fourth-generation synchrotron radiation sources. The detector has 768 channels of buffered counters with a maximum linear countrate per channel exceeding 2 MHz. With an overall countrate of similar to2 GHz, this detector is approximately 100 times faster than any other presently available. The 48 mum spacing from channel to channel also provides excellent spatial resolution, and thus also excellent energy resolution with dispersive spectrometers. This detector represents several improvements in reliability and ruggedness over an earlier prototype. The detector is capable of operating in a typical UHV environment and is presently installed in a Scienta electron analyzer at the ALS for testing and first data taking. A total countrate exceeding 1 GHz and a position resolution of about two channels have been experimentally demonstrated. It should be possible to read out all 768 channels in as little as 150 mus for time-resolved and pump-probe experiments. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Bussat, JM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 3 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 945 EP 948 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000232 ER PT S AU Siddons, DP Beuttenmuller, RH O'Connor, P Kuczewski, AJ Li, Z AF Siddons, DP Beuttenmuller, RH O'Connor, P Kuczewski, AJ Li, Z BE Warwick, T Arthur, J Padmore, HA Stohr, J TI The BNL silicon multi-element detector system for dilute EXAFS experiments SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB In order to meet the challenges of EXAFS and XANES spectroscopy of dilute systems, a custom integrated circuit has been fabricated which integrates 32 complete energy resolving photon counting chains onto a 6mm x 4mm chip. This paper reports on initial tests of a 96-element detector implementation using low-leakage diodes fabricated at BNL, and on our plans for a 384-channel version. This large array will initially also use the same diodes but eventually wilt use a hexagonal drift-detector array. The ASIC is read out through an embedded microcontroller device, and a software package has been written to allow highly automated setup of the entire system and straightforward integration into standard data acquisition packages. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Siddons, DP (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 3 TC 7 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 953 EP 956 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000234 ER PT S AU Cheong, SK Liu, JY Powell, CF Wang, J AF Cheong, SK Liu, JY Powell, CF Wang, J BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Application of an avalanche photodiode in synchrotron-based ultra-fast X-radiography SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID FUEL SPRAYS; DETECTOR AB A possibility of using avalanche photodiode has been investigated while operated in current or continuous wave mode to accommodate high-intensity synchrotron x-ray beams in an ultra-fast x-radiography. To achieve a time resolution of 1 mus or better in a time-resolved x-radiograhic experiment, the entire time-sequence of the APD response to the pulsed synchrotron x-ray beam is recorded with time resolution of 1-2 ns. We have characterized the APD detector in the continuous wave mode to reveal its linearity, signal to noise ratio, and the time response with various circuit configurations. We have demonstrated that signal-to-noise ratio better than 1000 can be achieved, which is limited only by Poisson statistics. These detectors, coupled with finely focused x-rays, have been used to study structure and dynamics of supersonic fuel sprays with 50 mum-spatial resolution and mus-temporal resolution in the region close to an injection nozzle. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Cheong, SK (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 4 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 961 EP 964 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000236 ER PT S AU Siddons, DP Camarda, G Kakuno, E AF Siddons, DP Camarda, G Kakuno, E BE Warwick, T Arthur, J Padmore, HA Stohr, J TI A cadmium-zinc-telluride strip detector for high-energy diffraction applications SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB As diffraction experiments in materials science move towards using harder x-rays, the need for efficient multidetectors in the form of 1- and 2-D arrays is felt. Silicon technologgy is not suitable for this, and germanium has the complexity of requiring cryogenics. Cadmium Zinc Telluride has emerged as the most promising compound for such applications. We describe our efforts towards providing a 1-D strip detector suitable for high-energy diffraction. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Siddons, DP (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 965 EP 968 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000237 ER PT S AU Ishii, H Johnson, B Brennan, S AF Ishii, H Johnson, B Brennan, S BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Performance of a dispersive analyzer for anomalous scattering measurements of amorphous materials SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID X-RAY-SCATTERING AB The partial pair distribution function (PPDF) of an amorphous material is the local environment of an element in the solid. For a two-component system, such as MoGe3, there are three PPDFs: Mo-Mo, Ge-Ge, and Mo-Ge. The PPDF can be derived from anomalous scattering measurements of the material, in this case collecting data near both the Mo and Ge K-absorption edges. Successful derivation of the PPDFs requires the removal of a number of error signals from the x-rays scattered from the sample. In addition to the elastically scattered light, there are both resonant Raman and Compton scattering. Although the resonant Raman Kalpha signal can be resolved using a solid-state detector, the resonant Raman Kbeta and Compton signals cannot. We have developed a variable focal length graphite analyzer which disperses these signals onto a position-sensitive detector. At each scattering angle, a spectrum of the scattered energies is recorded. These spectra are then deconvolved and the elastic signal is integrated. In this paper we present the design and implementation of the analyzer, discussing error sources such as focusing and mechanical compliance. C1 Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Ishii, H (reprint author), Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. NR 11 TC 1 Z9 1 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 969 EP 972 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000238 ER PT S AU Fakra, S Kilcoyne, ALD Tyliszczak, T AF Fakra, S Kilcoyne, ALD Tyliszczak, T BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Scintillator detectors for scanning transmission x-ray microscopes at the advanced light source SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB The choice of x-ray detectors presents a challenge for scanning transmission x-ray microscopes (STXM). The ultimate detector for the ALS STXMs should have a very high efficiency over a wide energy range, single photon counting capabilities up to 1GHz, high rejection of red laser light, fast response, and work in both vacuum and at atmospheric pressure. The results of an investigation using a photomultiplier tube (PMT) with a number of different scintillators are presented. The PMT is used in photon counting and analog modes. Scintillators used for this study include commercially available phosphor powders and various single crystals. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fakra, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Kilcoyne, David/I-1465-2013 NR 2 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 973 EP 976 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000239 ER PT S AU Rogers, JH Bargar, JR Waychunas, GA Yoon, TH Brown, GE AF Rogers, JH Bargar, JR Waychunas, GA Yoon, TH Brown, GE BE Warwick, T Arthur, J Padmore, HA Stohr, J TI A novel spectrometer system for hard x-ray interfacial environmental chemistry SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID PB(II) AB A new high-precision spectrometer system has been developed and tested for measuring grazing-incidence XAFS spectra, x-ray reflectivity, and standing wave intensity data from adsorbates on oriented single crystals and flat polycrystalline samples. The instrument system was designed for routine, rapid installation and alignment in synchrotron experimental hutches utilized for XAFS measurements. Two major components comprise the system: (a) a strongback cradle on which flexor slits, sample positioners, and detectors are aligned, and (b) a multi-altitudinal detector support, which allows a 30-element Ge detector array to be positioned at vertical down-looking, horizontal side-looking, and intermediate observation angles. Motorized positioners provide seven axes of motion for samples, which allows accurate positioning of large sample cells and samples having uneven shapes. Precision slits located upstream of the sample provide aperture control to about I micron precision over a range of motion from zero to 1.5 mm, making possible measurements on mm-diameter samples at very small incidence angles (similar to0.15degrees). An ion chamber detector located downstream of the sample is mounted on a bearing arc to rotate about the sample eucentric for specular reflectivity measurements. This detector can be replaced with an analyzer crystal and proportional counter to provide high-rate counting with high angular/energy resolution. Results from recent measurements demonstrate the utility and precision of this instrument for molecular environmental interface science. C1 Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Rogers, JH (reprint author), Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. NR 7 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 981 EP 984 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000241 ER PT S AU Friedrich, S Drury, OB Funk, T Sherrell, D Yachandra, VK Labov, SE Cramer, SP AF Friedrich, S Drury, OB Funk, T Sherrell, D Yachandra, VK Labov, SE Cramer, SP BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Superconducting high-resolution x-ray spectrometers for chemical state analysis of dilute samples SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID TUNNEL-JUNCTION; PERFORMANCE; DETECTORS AB Cryogenic X-ray spectrometers operating at temperatures below I K combine high energy resolution with broadband efficiency for X-ray energies up to 10 keV. They offer advantages for chemical state analysis of dilute samples by fluorescence-detected X-ray absorption spectroscopy (XAS) in cases where conventional Ge or Si(Li) detectors lack energy resolution and grating spectrometers lack detection efficiency. We are developing soft X-ray spectrometers based on superconducting Nb-Al-AlOx-Al-Nb tunnel junction (STJ) technology. X-rays absorbed in one of the superconducting electrodes generate excess charge carriers in proportion to their energy, thereby producing a measurable temporary increase in tunneling current. For STJ operation at the synchrotron, we have designed a two-stage adiabatic demagnetization refrigerator (ADR) with a cold finger that holds a 3 x 3 array of STJs inside the UHV sample chamber at a temperature of similar to0.1 K within similar to15 mm of a room temperature sample. Our STJ spectrometer can have an energy resolution below 10 eV FWHM for X-ray energies up to 1 keV, and has total count rate capabilities above 100,000 counts/s. We will describe detector performance in synchrotron-based X-ray fluorescence experiments and demonstrate its use for XAS on a dilute metal site in a metalloprotein. C1 Lawrence Livermore Natl Lab, Adv Detector Grp, Livermore, CA 94550 USA. RP Friedrich, S (reprint author), Lawrence Livermore Natl Lab, Adv Detector Grp, L-270, Livermore, CA 94550 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 985 EP 988 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000242 ER PT S AU Siddons, DP AF Siddons, DP BE Warwick, T Arthur, J Padmore, HA Stohr, J TI An x-ray michelson interferometer with low intrinsic time dispersion. SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID DYNAMICAL DIFFRACTION; PERFECT CRYSTALS AB The SPPS and LCLS are next-generation light sources which will produce ultra-short x-ray pulses a few 10's of femtoseconds long, with large numbers of photons per pulse. The development of instruments to characterize the temporal proper-ties of these beams is of significant interest. We present in this paper a concept and initial experiments towards the fabrication of an x-ray interferometer suitable for this purpose. It makes use of the temporal focusing properties of the T-2T-T Bonse-Hart interferometer to minimize the influence of the time-dispersion of the instrument on the overall response function. Separate path-length shifters based on an elastically deforming perfect crystal device are used to scan the time delay. Path-length differences of up to 0.1mm should be possible using this shifter design. An advantage of this design compared to others is that there is in principle no limit to the possible path length shift. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Siddons, DP (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. NR 10 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 997 EP 1000 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000245 ER PT S AU Guo, JH Augustsson, A Englund, C Nordgren, J AF Guo, JH Augustsson, A Englund, C Nordgren, J BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Resonant soft-x-ray emission spectroscopy of liquids SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB We present now a possible way to carry out soft-x-ray fluorescence spectroscopy of liquids. The liquid cell has a window to attain compatibility with UHV conditions of the spectrometer and beamline, The synchrotron radiation enters the liquid cell through a 100 nm-thick silicon nitride window and the emitted x-rays exit through the same window. This allows in particular liquid-solid interfaces to be studied. Such a liquid cell has been used to study the electronic structure of a variety of systems ranging from water solutions of inorganic salts and inertial drugs to nano materials and actinide compounds in their wet conditions. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA USA. RP Guo, JH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1066 EP 1069 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000262 ER PT S AU Feng, J MacDowell, AA Duarte, R Doran, A Forest, E Kelez, N Marcus, M Munson, D Padmore, H Petermann, K Raoux, S Robin, D Scholl, A Schlueter, R Schmid, P Stohr, J Wan, W Wei, DH Wu, Y AF Feng, J MacDowell, AA Duarte, R Doran, A Forest, E Kelez, N Marcus, M Munson, D Padmore, H Petermann, K Raoux, S Robin, D Scholl, A Schlueter, R Schmid, P Stohr, J Wan, W Wei, DH Wu, Y BE Warwick, T Arthur, J Padmore, HA Stohr, J TI An aberration corrected Photoemission electron microscope at the Advanced Light Source SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID DESIGN AB Design of a new aberration corrected Photoemission electron microscope PEEM3 at the Advanced Light Source is outlined. PEEM3 will be installed. on an elliptically polarized undulator beartiline and will be used for the study of complex materials at high spatial and spectral resolution. The critical components of PEEM3 are the electron mirror aberration corrector and aberration-free magnetic beam separator. The models to calculate the optical properties of the electron mirror are discussed. The goal of the PEEM3 project is to achieve the highest possible transmission of the system at resolutions comparable to our present PEEM2 system (50 nm) and to enable significantly higher resolution, albeit at the sacrifice of intensity. We have left open the possibility to add an energy filter at a later date, if it becomes necessary driven by scientific need to improve the resolution further. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RP Feng, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. RI MacDowell, Alastair/K-4211-2012; Scholl, Andreas/K-4876-2012; Raoux, Simone/G-3920-2016 NR 7 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1070 EP 1073 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000263 ER PT S AU Lienert, U Almer, J Haeffner, D Gao, Y Carter, W AF Lienert, U Almer, J Haeffner, D Gao, Y Carter, W BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Nondestructive strain tensor scanning within samples of cylindrical symmetry SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID DIFFRACTION; SLIT AB The radial (i.e., depth below the surface) dependence of the residual strain tensor within shot-peened samples of cylindrical geometry is measured nondestructively using high-energy synchrotron radiation (80 keV). Transmission geometry is employed in combination with a triangulation slit and area detector. Thus, a radial gauge length is defined directly by the beam size rather than cumulatively as in conventional reflection geometry. A narrow incident beam of 30 micrometer diameter is used, and we demonstrate that macroscopic grain averaging is achieved even in the bulk, where the grain size is large, by oscillating the samples in two dimensions. Therefore, the samples are rotated with high frequency around the cylinder axis and translated with low frequency parallel to the axis. We argue that the combination of a narrow incident beam, a two-dimensional sample oscillation, and area detector Provides a versatile technique to overcome insufficient grain averaging as the gauge volumes can be flexibly chosen by the combined translation and/or rotation oscillations. The methodology is discussed and experimental results are presented for a shot-peened steel sample. The achieved radial resolution is 30 micrometers, and the radial dependences of five strain tensor components are measured. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Lienert, U (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1074 EP 1077 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000264 ER PT S AU Singh, A Luening, K Brennan, S Homma, T Kubo, N Pianetta, P AF Singh, A Luening, K Brennan, S Homma, T Kubo, N Pianetta, P BE Warwick, T Arthur, J Padmore, HA Stohr, J TI The nucleation and growth of Cu nanoclusters on silicon surfaces SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB Due to the recent adoption of copper interconnect technology by the semiconductor industry, there has been great interest in understanding the kinetics and mechanisms of copper metal deposition on silicon wafer surfaces in ultra pure water (UPW) solutions. To study the kinetics of the copper deposition mechanism on silicon surfaces, silicon [100] samples were immersed in non-deoxygenated and deoxygenated UPW solutions contaminated with a copper concentration of 100 ppb with dipping times ranging from 5 to 300 seconds and then measured using total reflection x-ray fluorescence (TXRF) at the Stanford Synchrotron Radiation Laboratory (SSRL). By measuring the Cu fluorescence signal as function of angle of incidence of the incoming x-rays, it was possible to ascertain whether the deposited copper was atomically dispersed or particle-like in nature. It was established that in non-deoxygenated UPW, the copper is incorporated atomically into the silicon surface oxide as a copper oxide, while in deoxygenated UPW, copper is deposited on the silicon surface in the form of nanoparticles. The heights of these particles were determined by performing quantitative fits to the angle scans using a spherical cap model to describe the Cu clusters. The results were consistent with measurements conducted with atomic force microscopy (AFM). Finally, the surface density of the metallic copper nanoparticles deposited in deoxygenated UPW was determined for the whole range of dipping times from the AFM measurements, indicating that Ostwald Ripening mechanisms, where large particles grow at the expense of smaller, less thermodynamically stable particles, describe the growth of Cu nanoclusters in deoxygenated UPW solutions. C1 Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Singh, A (reprint author), Stanford Synchrotron Radiat Lab, 2575 Sand Hill Rd, Stanford, CA 94309 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1086 EP 1089 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000267 ER PT S AU Attenkofer, K Adams, BW Beno, MA AF Attenkofer, K Adams, BW Beno, MA BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Instrumentation for time-dependent x-ray resonant Raman scattering SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB X-ray absorption/fluorescence spectroscopy probes valence states relative to a core level and thus provides an absolute energy reference. The core hole lifetime broadening can be reduced by restricting the fluorescence signal with a sub-eV crystal energy analyzer. We describe the design and first performance tests of adaptive optics for a bent-crystal analyzer which is characterized by a high counting efficency and a large solid angle acceptance. The device was designed for the determination of charge carrier dynamics in photoexcited semiconductors in laser pump, x-ray probe experiments. It can also be used in a wide range of near-edge spectroscopic applications and as an ultrafast laser/x-ray cross correlator.. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Attenkofer, K (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1138 EP 1141 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000280 ER PT S AU Arenholz, E Prestemon, SO AF Arenholz, E Prestemon, SO BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Octupole magnet for soft x ray magnetic dichroism experiments: Design and performance SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID CIRCULAR-DICHROISM AB An octupole magnet endstation for soft x ray magnetic dichroism measurements has been developed at the Advanced Light Source. The system consists of an eight pole electromagnet that surrounds a small vacuum chamber. The magnet provides fields up to 0.9 T that can be applied in any direction relative to the incoming x ray beam. High precision magnetic circular and linear dichroism spectra can be obtained reversing the magnetic field for each photon energy in an energy scan. Moreover, the field dependence of all components of the magnetization vector can be studied in detail by choosing various angles of x ray incidence while keeping the relative orientation of magnetic field and sample fixed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Arenholz, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 7 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1170 EP 1173 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000288 ER PT S AU Siddons, DP Liss, KD Hastings, JB Grubel, G AF Siddons, DP Liss, KD Hastings, JB Grubel, G BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Nuclear fluorescence using high-energy synchrotron radiation SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB We present some measurements of nuclear fluorescence which were made while exploring the potential of a unique source of very hard x-rays which was installed at ESRF until recently. It produced radiation of energies up to 1 MeV. In this range there are many nuclear resonances, and so we made a small survey of some plausible candidates to see if they could indeed be excited using this source. Along with short-lived resonances, we were also able to indirectly populate long-lived isomeric states in several nuclei. Thus, simply exposing the samples to the white beam for a period of time caused them to be activated. The samples could them be removed from the beam and their emissions observed using an energy-resolving detector. Isomeric states in isotopes of indium, cadmium and silver were excited and their subsequent decay observed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Siddons, DP (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Liss, Klaus-Dieter/E-8548-2011 OI Liss, Klaus-Dieter/0000-0003-4323-0343 NR 3 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1178 EP 1181 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000290 ER PT S AU Shu, D Preissner, C Nocher, D Han, Y Barraza, J Lee, P Lee, WK Cai, Z Ginell, S Alkire, R Lazarski, K Schuessler, R Joachimiak, A AF Shu, D Preissner, C Nocher, D Han, Y Barraza, J Lee, P Lee, WK Cai, Z Ginell, S Alkire, R Lazarski, K Schuessler, R Joachimiak, A BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Design and development of a robot-based automation system for cryogenic crystal sample mounting at the advanced photon source SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB X-ray crystallography is the primary method to determine the 3D structures of complex macromolecules at high resolution. In the years to come, the Advanced Photon Source (APS) and similar 3(rd)-generation synchrotron sources elsewhere will become the most powerful tools for studying atomic structures of biological molecules. One of the major bottlenecks in the x-ray data collection process is the constant need to change and realign the crystal sample. This is a very time- and manpower-consuming task. An automated sample mounting system will help to solve this bottleneck problem. We have developed a novel robot-based automation system for cryogenic crystal sample mounting at the APS. Design of the robot-based automation system, as well as its on-line test results at the Argonne Structural Biology Center (SBC) 19-BM experimental station, are presented in this paper. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Shu, D (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1201 EP 1204 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000295 ER PT S AU Miller, MD Brinen, LS Cohen, A Deacon, AM Ellis, P McPhillips, SE McPhillips, TM Phizackerley, RP Soltis, SM van den Bedem, H Wolf, G Xu, QP Zhang, ZP AF Miller, MD Brinen, LS Cohen, A Deacon, AM Ellis, P McPhillips, SE McPhillips, TM Phizackerley, RP Soltis, SM van den Bedem, H Wolf, G Xu, QP Zhang, ZP BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Automation of high-throughput crystal screening and data collection at SSRL SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID SYSTEM AB A robotic system for auto-mounting crystals from liquid nitrogen is now operational on SSRL beamlines (Cohen et al., J. Appl. Cryst. (2002). 35, 720-726). The system uses a small industrial 4-axis robot with a custom built actuator. Once mounted, automated alignment of the sample loop to the X-ray beam readies the crystal for data collection. After data collection, samples are returned to the cassette. The beamline Dewar accommodates three compact sample cassettes (holding up to 96 samples each). During the past 4 months, the system on beamiline 11-1 has been used to screen over 1000 crystals. The system has reduced both screening time and manpower. Integration of the hardware components is accomplished in the Distributed Control System architecture developed at SSRL (McPhillips et al., J. Synchrotron Rad. (2002) 9, 401-406). A crystal-screening interface has been implemented in Blu-Ice. Sample details can be uploaded from an Excel spreadsheet. The JCSG generates these spreadsheets automatically from their tracking database using standard database tools (http://www.jcsg.org). New diffraction image analysis tools are being employed to aid in extracting results. Automation also permits tele-presence. For example, samples have been changed during the night without leaving home and scientists have screened crystals 1600 miles from the beamline. The system developed on beamline 11-1 has been replicated onto 1-5, 9-1, 9-2, and 11-3 and is used by both general users and the JCSG. C1 SLAC, Stanford Synchrotron Radiat Lab, Joint Ctr Struct Genom, Menlo Pk, CA 94025 USA. RP Miller, MD (reprint author), SLAC, Stanford Synchrotron Radiat Lab, Joint Ctr Struct Genom, MS 69,2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. NR 3 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1233 EP 1236 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000303 ER PT S AU Stojanoff, V Venkatagiriyappa, V Jakoncic, J Yin, Z Allaire, M AF Stojanoff, V Venkatagiriyappa, V Jakoncic, J Yin, Z Allaire, M BE Warwick, T Arthur, J Padmore, HA Stohr, J TI The NIGMS X6A east coast structural biology facility SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB The X6A facility at the National Synchrotron Light Source (NSLS) is a dedicated macromolecular crystallography beam line funded by the National Institute of General Medical Sciences. The facility serves expert and non-expert crystallographers from protein purification to the determination of atomic coordinates. The X6A facility consists of an experimental station and an associated laboratory for sample preparation. The X6A beam line optics include an NSLS design Si(111) channel-cut monochromator and an Oxford Danfysik toroidal focusing mirror. The end station consists of a CrystalLogic Kappa diffractometer and an ADSC 210 CCD detector. Standard crystallographic packages are available to assist the users for data analysis. An automated sample changer will be added in the near future to the end station. The associated laboratory is fully equipped for all aspects of protein purification and crystallization. The beam line is currently available for users (http://protein.nsls.bnl.gov). The main goal of the X6A effort is to provide the basic tools to researchers who would like to use macromolecular crystallography and structural biology to address important biological questions. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Stojanoff, V (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RI stojanoff, vivian /I-7290-2012 OI stojanoff, vivian /0000-0002-6650-512X NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1237 EP 1240 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000304 ER PT S AU Doran, A Scholl, A Feng, J Chao, WL Anderson, E Padmore, H AF Doran, A Scholl, A Feng, J Chao, WL Anderson, E Padmore, H BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Comprehensive electron-optical characterization of an x-ray photoemission electron microscope SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB Typically the performance of Photoemission Electron Microscopes (PEEM) is reported as one number, representative of a microscope's ultimate performance under an ideal set of conditions. Often a simple Rayleigh criterion is used which defines the spatial resolution approximately as the minimum distance of two still distinguishable features. However, the ability of an instrument to provide meaningful spectroscopic and microscopic information depends on the contrast loss of a pattern over a much wider range of spatial frequencies. For example, the chemical signature of one area on the sample can be contaminated from an adjacent area although both areas are still easily distinguishable in a microscopic image. We report here on a more comprehensive measurement of the PEEM-II instrument at beamline 7.3. 1.1 at the Advanced Light Source (ALS) that examines the response of the instrument to a wide range of experimental conditions. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Adv Light Source, Expt Syst Grp, Berkeley, CA 94720 USA. RP Doran, A (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Adv Light Source, Expt Syst Grp, Berkeley, CA 94720 USA. RI Scholl, Andreas/K-4876-2012 NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1279 EP 1282 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000314 ER PT S AU Shu, D Maser, J Lai, B Vogt, S AF Shu, D Maser, J Lai, B Vogt, S BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Design for an X-ray nanoprobe prototype with a sub-10-nm positioning requirement SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID LINEAR-ACTUATOR; RESOLUTION AB We are developing a new hard x-ray nanoprobe beamline with 30 nm resolution at the Advanced Photon Source (APS). Imaging and spectroscopy at this resolution level require staging of x-ray optics and specimens with a mechanical repeatability of better than 10 nm. We have developed a prototype instrument with a novel interferometrically controlled scanning stage system. The system consists of nine DC-motordriven stages, four picomotor-driven stages, and two PZT-driven stages. An APS-designed custom-built laser Doppler displacement meter system provides two-dimensional differential displacement measurement with subnanometer resolution between the zone-plate x-ray optics and the sample holder. Also included is the alignment and stable positioning of two stacked zone plates for increasing the focusing efficiency. The entire scanning system was designed with high stiffness, high repeatability, low drift, flexible scanning schemes, and possibility of fast feedback for differential motion. Designs of the scanning stage system, as well as preliminary mechanical test results, are presented in this paper. C1 Argonne Natl Lab, Ctr Nanoscale Mat, Argonne, IL 60439 USA. RP Shu, D (reprint author), Argonne Natl Lab, Ctr Nanoscale Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Maser, Jorg/K-6817-2013; Vogt, Stefan/B-9547-2009; Vogt, Stefan/J-7937-2013 OI Vogt, Stefan/0000-0002-8034-5513; Vogt, Stefan/0000-0002-8034-5513 NR 10 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1287 EP 1290 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000316 ER PT S AU Vogt, S Feser, A Legnini, D Kirz, J Maser, J AF Vogt, S Feser, A Legnini, D Kirz, J Maser, J BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Fast differential phase-contrast imaging and total fluorescence yield mapping in a hard X-ray fluorescence microprobe SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID MICROSCOPY; DETECTOR AB We have incorporated differential phase-contrast (DPC) detection in a hard x-ray fluorescence microprobe at the Advanced Photon Source. We report a straightforward implementation of unidirectional DPC and demonstrate that it is highly advantageous for imaging low-Z specimens with hard x-rays (10keV). Phase-contrast imaging of a specimen can be used to acquire fast overview images of samples that allow more precise targeting of time consuming fluorescence scans. In order to get an overview of the elemental content of a specimen in these fly-scans, we have also implemented a fast detection of total fluorescence yield. Additionally, a DPC image of the specimen is obtained simultaneously with the fluorescence maps in normal step-scanning mode, to facilitate a direct comparison and co-registration with visible light micrographs. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Vogt, S (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Maser, Jorg/K-6817-2013; Vogt, Stefan/B-9547-2009; Vogt, Stefan/J-7937-2013 OI Vogt, Stefan/0000-0002-8034-5513; Vogt, Stefan/0000-0002-8034-5513 NR 13 TC 5 Z9 5 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1348 EP 1351 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000331 ER PT S AU Tyliszczak, T Warwick, T Kilcoyne, ALD Fakra, S Shuh, DK Yoon, TH Brown, GE Andrews, S Chernbrolu, V Strachan, J Acremann, Y AF Tyliszczak, T Warwick, T Kilcoyne, ALD Fakra, S Shuh, DK Yoon, TH Brown, GE Andrews, S Chernbrolu, V Strachan, J Acremann, Y BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Soft X-ray scanning transmission microscope working in an extended energy range at the advanced light source SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB One of the ALS scanning transmission x-ray microscopes (STXMs) has been moved to the new ALS molecular environmental science beamline 11.0.2. The STXM is located on the microscopy branchline downstream of an elliptically-polarizing undulator delivering x-rays from 80 eV to 1900 eV. The wide energy range allows STXM operations with the current zone plate from 190 eV to about 1900 eV, the highest accessible energy with sufficient flux. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Tyliszczak, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Kilcoyne, David/I-1465-2013 NR 3 TC 32 Z9 32 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1356 EP 1359 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000333 ER PT S AU Choe, SB Acremann, Y Bauer, A Scholl, A Doran, A Stohr, J Padmore, HA AF Choe, SB Acremann, Y Bauer, A Scholl, A Doran, A Stohr, J Padmore, HA BE Warwick, T Arthur, J Padmore, HA Stohr, J TI P-sec time-resolved microscopy of magnetic structures using X-PEEM SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB A pump-probe setup has been developed at the Advanced Light Source for the microscopic investigation of p-sec dynamics using a synchronized Laser-X-ray Photoemission Electron Microscope. This setup is optimized for the investigation of magnetization dynamics in small structures. First experiments have been conducted on waveguides at a time resolution of 100 ps and a spatial resolution of 100 nm. The deflection of the photoexcited electrons in the microscope by the transient potential on the waveguide is a useful means for finding time zero and for determining the shape of the field pulse. C1 Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Choe, SB (reprint author), Ernest Orlando Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RI Scholl, Andreas/K-4876-2012 NR 1 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1391 EP 1394 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000341 ER PT S AU Adams, BW AF Adams, BW BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Subpicosecond coherent manipulation of X-rays SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID PENDELLOSUNG FRINGES; DISTORTED CRYSTALS; DYNAMICAL THEORY; DIFFRACTION; THEORIE AB The Takagi-Taupin theory is synthesized with the eikonal theory in a unified space-time approach, based upon microscopic electromagnetism. It is designed specifically to address x-ray diffraction in crystal structures being modified within down to a few femtosconds. Possible applications in the subpicosecond coherent manipulation of x-rays are given. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Adams, BW (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1395 EP 1398 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000342 ER PT S AU Brewe, DL Heald, SA Stern, EA Beck, KM Feng, Y AF Brewe, DL Heald, SA Stern, EA Beck, KM Feng, Y BE Warwick, T Arthur, J Padmore, HA Stohr, J TI High efficiency XAFS data collection with sub-nanosecond time resolution SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP Conference Proceedings LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab AB Synchrotron-based laser pump/x-ray probe experiments on a ns or faster time scale have typically used ultrafast lasers suffering from the limitation of low repetition rates on the order of 1-10 kHz. This severely limits the data collection efficiency, since the x-ray bunches repeat at a much higher rate. This is particularly critical for XAFS experiments, which require very large S/N ratios (similar to 10(4) or better) to extract useful EXAFS far above the absorption edge. PNC-CAT has developed an apparatus based on a laser repeating at the rate of the APS bunch repetition frequency of 272 kHz, allowing an increase in data collection efficiency by two orders of magnitude. We have used this apparatus to obtain preliminary results for the time-resolved EXAFS from a 200nm thick polycrystalline Ge film which has been heated by the laser. C1 Argonne Natl Lab, Adv Photon Source, Sector 20, Pacific NW Consortium Collaborat Access Team, Argonne, IL 60439 USA. RP Brewe, DL (reprint author), Argonne Natl Lab, Adv Photon Source, Sector 20, Pacific NW Consortium Collaborat Access Team, Argonne, IL 60439 USA. NR 4 TC 1 Z9 1 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1399 EP 1402 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000343 ER PT S AU Schoenlein, RW Cavalleri, A Chong, HHW Glover, TE Heimann, PA Zholents, AA Zolotorev, MS AF Schoenlein, RW Cavalleri, A Chong, HHW Glover, TE Heimann, PA Zholents, AA Zolotorev, MS BE Warwick, T Arthur, J Padmore, HA Stohr, J TI Generation of femtosecond synchrotron pulses: Performance and characterization SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID X-RAY PULSES; RADIATION AB Femtosecond synchrotron pulses of <200 fs duration are generated at the Advanced Light Source beamline 5.3.1 via laser manipulation of the stored electron beam. We demonstrate a peak laser acceleration of >13 MeV relative to the nominal 1.9 GeV beam energy. Femtosecond pulses are effectively isolated from the long-pulse background using the transverse dispersion of the storage ring in combination with an x-ray imaging optic and a pair of slits to achieve a signal/background ratio of similar to1. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Schoenlein, RW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Schoenlein, Robert/D-1301-2014 OI Schoenlein, Robert/0000-0002-6066-7566 NR 4 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1403 EP 1406 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000344 ER PT S AU Heimann, PA Padmore, HA Schoenlein, RW AF Heimann, PA Padmore, HA Schoenlein, RW BE Warwick, T Arthur, J Padmore, HA Stohr, J TI ALS Beamline 6.0 for ultrafast X-ray absorption spectroscopy SO SYNCHROTRON RADIATION INSTRUMENTATION SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 8th International Conference on Synchrotron Radiation Instrumentation (SRI 2003) CY AUG 25-29, 2003 CL San Francisco, CA SP Lawrence Berkeley Natl Lab Adv Light Source, Stanford Synchrotron Radiat Lab ID SYNCHROTRON-RADIATION AB ALS Beamline 6.0 is designed for x-ray absorption spectroscopy with femtosecond x-ray pulses generated by the bunch 'slicing' technique. The fs x-ray pulses are isolated by imaging the source and translating slits a small vertical distance from the optical axis. Soft and hard x-ray branch lines will cover a wide photon energy range from 120 eV to 10 keV. A soft x-ray spectrograph will collect absorption spectra dispersively. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Heimann, PA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Schoenlein, Robert/D-1301-2014 OI Schoenlein, Robert/0000-0002-6066-7566 NR 7 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0180-2 J9 AIP CONF PROC PY 2004 VL 705 BP 1407 EP 1410 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Optics SC Instruments & Instrumentation; Nuclear Science & Technology; Optics GA BAG55 UT WOS:000222089000345 ER PT S AU Cheng, MD Jenkins, CM AF Cheng, MD Jenkins, CM BE Armstrong, R Thadhani, N Wilson, W Gilman, J Simpson, R TI Characterization of airborne ultrafine and nanometer particles during energetic material synthesis and testing SO SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF ENERGETIC/REACTIVE NANOMATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Synthesis, Characterization and Properties of Energetic/Reactive Nanomaterials held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc ID INCREASED PULMONARY TOXICITY AB Several experiments were conducted to improve our understanding of the properties of aerosol particles generated by detonation of conventional explosive and explosives prepared from nanophase materials. Initial number concentrations (similar to 10(6)-10(7) cm(-3)) of particles produced by detonations of the nano-explosives were comparable to that produced by conventional explosive. In general, data taken by a time-of-flight aerodynamic sizer and a scanning differential mobility analyzer for the first sample indicate a multi-modal distribution that there were a peak between 0.7 and 0.9 mum, and one and/or two peaks smaller than 100 nm depending upon the explosive used. The material properties and formulation of the explosive appear to play a significant role in the enhanced particle growth and increased deposition velocity leading to a higher reduction rate of total particle concentrations. Furthermore, the high level of ultrafine particles and nanoparticles in addition to the enriched toxic metals, the biological properties (e.g., the cellular toxicity) of the detonation particles need to be investigated in the near future. C1 Oak Ridge Natl Lab, ESD, Oak Ridge, TN 37831 USA. RP Cheng, MD (reprint author), Oak Ridge Natl Lab, ESD, Bldg 1505,MS 6038, Oak Ridge, TN 37831 USA. RI Cheng, Meng-Dawn/C-1098-2012; OI Cheng, Meng-Dawn/0000-0003-1407-9576 NR 9 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-738-5 J9 MATER RES SOC SYMP P PY 2004 VL 800 BP 39 EP 44 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BY95X UT WOS:000189504700004 ER PT S AU Gash, AE Satcher, JH Simpson, RL Clapsaddle, BJ AF Gash, AE Satcher, JH Simpson, RL Clapsaddle, BJ BE Armstrong, R Thadhani, N Wilson, W Gilman, J Simpson, R TI Nanostructured energetic materials with sol-gel methods SO SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF ENERGETIC/REACTIVE NANOMATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Synthesis, Characterization and Properties of Energetic/Reactive Nanomaterials held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc ID MONOLITHS; EPOXIDES; CONTACT AB The utilization of sol-gel chemical methodology to prepare nanostructured energetic materials as well as the concepts of nanoenergetics is described. The preparation and characterization of two totally different compositions is detailed. In one example, nanostructured aerogel and xerogel composites of sol-gel iron (III) oxide and ultra fine grained aluminum (UFG Al) are prepared, characterized, and compared to a conventional micron-sized Fe2O3/Al thermite. The exquisite degree of mixing and intimate nanostructuring of this material is illustrated using transmission and scanning electron microscopies (TEM and SEM). The nanocomposite material has markedly different energy release (burn rate) and thermal properties compared to the conventional composite, results of which will be discussed. Small-scale safety characterization was per-formed on the nanostructured thermite. The second nanostructured energetic material consists of a nanostructured hydrocarbon resin fuel network with fine ammonium perchlorate (NH4ClO4) oxidizer present. C1 Lawrence Livermore Natl Lab, Energet Mat Ctr, Livermore, CA 94551 USA. RP Gash, AE (reprint author), Lawrence Livermore Natl Lab, Energet Mat Ctr, POB 5508, Livermore, CA 94551 USA. NR 16 TC 1 Z9 2 U1 2 U2 12 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-738-5 J9 MATER RES SOC SYMP P PY 2004 VL 800 BP 55 EP 66 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BY95X UT WOS:000189504700006 ER PT S AU Clapsaddle, BJ Zhao, LH Gash, AE Satcher, JH Shea, KJ Pantoya, ML Simpson, RL AF Clapsaddle, BJ Zhao, LH Gash, AE Satcher, JH Shea, KJ Pantoya, ML Simpson, RL BE Armstrong, R Thadhani, N Wilson, W Gilman, J Simpson, R TI Synthesis and characterization of mixed metal oxide nanocomposite energetic materials SO SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF ENERGETIC/REACTIVE NANOMATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Synthesis, Characterization and Properties of Energetic/Reactive Nanomaterials held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc ID SOL-GEL SYNTHESIS; MONOLITHS; EPOXIDES AB In the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology, affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sot-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Furthermore, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. As a result, the desired organic functionality is well dispersed throughout the composite material on the nanoscale. By introducing a fuel metal into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of these metal oxide/silicon oxide nanocomposites and their performance as energetic materials will be discussed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Clapsaddle, BJ (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. NR 7 TC 1 Z9 3 U1 0 U2 7 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-738-5 J9 MATER RES SOC SYMP P PY 2004 VL 800 BP 91 EP 96 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BY95X UT WOS:000189504700010 ER PT S AU Son, SF AF Son, SF BE Armstrong, R Thadhani, N Wilson, W Gilman, J Simpson, R TI Performance and characterization of nanoenergetic materials at Los Alamos SO SYNTHESIS, CHARACTERIZATION AND PROPERTIES OF ENERGETIC/REACTIVE NANOMATERIALS SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Synthesis, Characterization and Properties of Energetic/Reactive Nanomaterials held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc ID ULTRAFINE ALUMINUM POWDERS; COMBUSTION; AIR AB Novel properties associated with nanostructured materials, including nanoenergetic materials, have attracted a great deal of interest recently. Metastable Intermolecular Composite (MIC) materials are comprised of a mixture of oxidizer and fuel with particle sizes in the nanometer range. They can have high energy densities and exhibit combustion velocities above 1 km/s. These properties make them very attractive in a number of applications, including lead-free primers and igniters. However characterizing these materials is challenging, and the mechanism responsible for the propagation of reaction in loose compacts is not well understood. In this paper I will present an overview of efforts at Los Alamos to characterize and better understand the reaction mechanisms of these advanced energetic materials. We also have continuing efforts to make new MIC materials. Two applications are illustrated for MIC materials. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Son, SF (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 18 TC 1 Z9 1 U1 0 U2 6 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-738-5 J9 MATER RES SOC SYMP P PY 2004 VL 800 BP 161 EP 172 PG 12 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing SC Materials Science GA BY95X UT WOS:000189504700018 ER PT J AU Reddy, GV Jacobs, HK Gopalan, AS Barrans, RE Dietz, ML Stepinski, DC Herlinger, AW AF Reddy, GV Jacobs, HK Gopalan, AS Barrans, RE Dietz, ML Stepinski, DC Herlinger, AW TI Synthesis of symmetrical methylenebis(alkyl hydrogen phosphonates) by selective cleavage of methylenebis(dialkyl phosphonates) with morpholine SO SYNTHETIC COMMUNICATIONS LA English DT Article DE bisphosphonic acids; metal ion extractants; bone disease ID SUBSTITUTED DIPHOSPHONIC ACIDS; ONE-POT SYNTHESIS; (DICHLOROMETHYLENE)BISPHOSPHONATE PARTIAL ESTERS; BISPHOSPHONATE CHELATING-AGENTS; IN-VITRO EVALUATION; SOLVENT-EXTRACTION; METAL EXTRACTION; 1-PHENYL-1-HYDROXYMETHYLENE BISPHOSPHONATE; MASS-SPECTROMETRY; AQUEOUS-SOLUTIONS AB The preparation of partial esters of methylenebisphosphonic acids has been of recent interest due to their potential therapeutic applications. This paper describes a convenient method to prepare symmetrical methylenebis(alkyl hydrogen phosphonates) by the selective cleavage of the corresponding methylenebis(dialkyl phosphonate) with refluxing morpholine. The effects of structural variations on the amine as well as the substrate have been investigated to understand the scope and limitations of this reaction. A superior approach to hindered bisphosphonic acid esters involves the cleavage of their dimethyl esters, 4, using morpholine. This method is also useful to access a number of C-alkyl dialkyl methylenebisphosphonic acids such as 6. This study clearly shows that cleavage with morpholine is convenient, inexpensive, and allows for the preparation of a variety of P,P'-disubstituted partial esters in good yields and high purity. C1 New Mexico State Univ, Dept Chem & Biochem, Las Cruces, NM 88003 USA. Loyola Univ, Dept Chem, Chicago, IL 60626 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Gopalan, AS (reprint author), New Mexico State Univ, Dept Chem & Biochem, MSC 3C, Las Cruces, NM 88003 USA. EM agopala@nmsu.edu FU NIGMS NIH HHS [S06 GM008136] NR 60 TC 12 Z9 12 U1 2 U2 3 PU MARCEL DEKKER INC PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0039-7911 J9 SYNTHETIC COMMUN JI Synth. Commun. PY 2004 VL 34 IS 2 BP 331 EP 344 DI 10.1081/SCC-120027271 PG 14 WC Chemistry, Organic SC Chemistry GA 778GA UT WOS:000189230100019 PM 23180889 ER PT S AU Brown, TL Patrick, DL Shamblin, DL Miller, TJ AF Brown, TL Patrick, DL Shamblin, DL Miller, TJ BE Valley, MT Vorontsov, MA TI Next generation laser tracker concepts SO TARGET-IN-THE-LOOP: ATMOSPHERIC TRACKING, IMAGING, AND COMPENSATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Target-in-the-Loop - Atmospheric Tracking, Imaging and Compensation CY AUG 04-05, 2004 CL Denver, CO SP SPIE DE laser tracking; atmospheric correction; atmospheric turbulence; anisoplanatic; Kalman filtering AB The current and future laser tracking mission requirements of Sandia National Laboratories are discussed. The capabilities of Sandia's existing laser trackers are summarized. The deficiencies of the current laser trackers are identified with respect to future mission requirements. Candidate commercial technologies are addressed to correct the identified deficiencies. Technology gap areas are identified where additional research needs to be conducted prior to developing an effective next generation laser tracking system. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Brown, TL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 4 TC 2 Z9 2 U1 1 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5490-7 J9 P SOC PHOTO-OPT INS PY 2004 VL 5552 BP 133 EP 146 DI 10.1117/12.561712 PG 14 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BBJ23 UT WOS:000225751300013 ER PT S AU Valley, MT AF Valley, MT BE Valley, MT Vorontsov, MA TI Uncertainty quantification for cooperative target tracking SO TARGET-IN-THE-LOOP: ATMOSPHERIC TRACKING, IMAGING, AND COMPENSATION SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Target-in-the-Loop - Atmospheric Tracking, Imaging and Compensation CY AUG 04-05, 2004 CL Denver, CO SP SPIE DE cooperative tracking; uncertainty quantification; optical tracking; pose estimation ID MOBILE ROBOTS; MOTION; LOCALIZATION; RECOGNITION; MODELS; FILTER AB Historically tracking systems have provided limited quantitative data such as approximate range, speed, and trajectory. Today's tracking systems are now being tasked with accurately quantifying a broader range of dynamic state variables (e.g., absolute and relative position, orientation, linear and angular velocity/acceleration, spin rate, trajectory, angle of attack, angle of impact) for high-speed test articles. This information is needed to demonstrate that the required test conditions are achieved, to develop, validate, and apply predictive models, and to document a system's response to a test environment. Few existing and emerging optical tracking methods accurately provide the dynamic state variables. Even fewer quantify the measurement uncertainty. Past measurement error estimates have been either qualitative or lacked the rigor needed to accurately validate and apply predictive models. This presentation will discuss tracking options and approaches for characterizing tracking measurement uncertainty. C1 Sandia Natl Labs, Albuquerque, NM 87175 USA. RP Valley, MT (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87175 USA. NR 52 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5490-7 J9 PROC SPIE PY 2004 VL 5552 BP 147 EP 158 DI 10.1117/12.561716 PG 12 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BBJ23 UT WOS:000225751300014 ER PT S AU Valley, M Shields, R Reed, J AF Valley, M Shields, R Reed, J BE Valley, MT Vorontsov, MA TI TrackEye tracking algorithm characterization SO TARGET-IN-THE-LOOP: ATMOSPHERIC TRACKING, IMAGING, AND COMPENSATION SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Target-in-the-Loop - Atmospheric Tracking, Imaging and Compensation CY AUG 04-05, 2004 CL Denver, CO SP SPIE DE TrackEye; cooperative tracking algorithm evaluation; uncertainty quantification; optical tracking; pose estimation AB TrackEye is a film digitization and target tracking system that offers the potential for quantitatively measuring the dynamic state variables (e.g., absolute and relative position, orientation, linear and angular velocity/acceleration, spin rate, trajectory, angle of attack, etc.) for moving objects using captured single or dual view image sequences. At the heart of the system is a set of tracking algorithms that automatically find and quantify the location of user selected image details such as natural test article features or passive fiducials that have been applied to cooperative test articles. This image position data is converted into real world coordinates and rates with user specified information such as the image scale and frame rate. Though tracking methods such as correlation algorithms are typically robust by nature, the accuracy and suitability of each TrackEye tracking algorithm is in general unknown even under good imaging conditions. The challenges of optimal algorithm selection and algorithm performance/measurement uncertainty are even more significant for long range tracking of high-speed targets where temporally varying atmospheric effects degrade the imagery. This paper will present the preliminary results from a controlled test sequence used to characterize the performance of the TrackEye tracking algorithm suite. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Valley, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5490-7 J9 P SOC PHOTO-OPT INS PY 2004 VL 5552 BP 179 EP 188 DI 10.1117/12.561616 PG 10 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BBJ23 UT WOS:000225751300017 ER PT B AU Insepov, Z Norem, JH Hassanein, A AF Insepov, Z Norem, JH Hassanein, A BE Akinwande, AI Chen, L Kymissis, I Hong, C TI New mechanism of cluster field evaporation in rf breakdown SO TECHNICAL DIGEST OF THE 17TH INTERNATIONAL VACUUM NANOELECTRONICS CONFERENCE LA English DT Proceedings Paper CT 17th International Vacuum Nanoelectronics Conference (IVNC 04) CY JUL 11-16, 2004 CL MIT, Cambridge, MA SP AVC, MIT, IEEE Elect Device Soc, Stellar Micro-Devices HO MIT C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Insepov, Z (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Insepov, Zinetula/L-2095-2013 OI Insepov, Zinetula/0000-0002-8079-6293 NR 0 TC 0 Z9 0 U1 2 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-8397-4 PY 2004 BP 180 EP 181 AR 122001 DI 10.1103/PhysRevSTAB.7.122001 PG 2 WC Engineering, Electrical & Electronic; Physics, Condensed Matter SC Engineering; Physics GA BBC46 UT WOS:000224760000077 ER PT J AU Ibragimova, EM Kalanov, MU Kirk, MA Foltyn, SR AF Ibragimova, EM Kalanov, MU Kirk, MA Foltyn, SR TI Effect of mechanical deformation on the critical current in YBa2Cu3O7-b superconducting films SO TECHNICAL PHYSICS LA English DT Article ID TAPES AB It is shown that local mechanical bending of YBa2Cu3O7 - b Ag-coated superconducting films deposited on flexible metal substrates in the temperature interval 77-300 K may increase the critical density J(c) of the transport current to values as high as 10(6) A/cm(2) or even higher at 77 K. Also, bending decreases the voltage criterion. This means a rise in the intergranular conductivity and, accordingly, a reduction of Joule losses. (C) 2004 MAIK "Nauka / Interperiodica". C1 Ukbek Acad Sci, Inst Nucl Phys, Tashkent 702132, Uzbekistan. Argonne Natl Lab, Argonne, IL 60439 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ibragimova, EM (reprint author), Ukbek Acad Sci, Inst Nucl Phys, Tashkent 702132, Uzbekistan. EM ibragimova@inp.uz NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1063-7842 J9 TECH PHYS+ JI Tech. Phys. PY 2004 VL 49 IS 4 BP 512 EP 515 DI 10.1134/1.1736926 PG 4 WC Physics, Applied SC Physics GA 812ZG UT WOS:000220876800025 ER PT B AU Krishnan, M Nieplocha, J AF Krishnan, M Nieplocha, J BE Tzeng, NF TI Optimizing parallel multiplication operation for rectangular and transposed matrices SO TENTH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS, PROCEEDINGS LA English DT Proceedings Paper CT 10th International Conference on Parallel and Distributed Systems (ICPADS 2004) CY JUL 07-09, 2004 CL Newport Beach, CA SP IEEE Comp Soc, TCPP, IEEE Comp Soc, TCDP AB In many applications, matrix multiplication involves different shapes of matrices. The shape of the matrix can significantly impact the performance of matrix multiplication algorithm. This paper describes extensions of the SRUMMA parallel matrix multiplication algorithm [1] to improve performance of transpose and rectangular matrices. Our approach relies on a set of hybrid algorithms which are chosen based on the shape of matrices and transpose operator involved. The algorithm exploits performance characteristics of clusters and shared memory systems: it differs from the other parallel matrix multiplication algorithms by the explicit use of shared memory and remote memory access (RMA) communication rather than message passing. The experimental results on clusters and shared memory systems demonstrate consistent performance advantages over pdgemm from the ScaLAPACK parallel linear algebra package. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Krishnan, M (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 33 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2152-5 PY 2004 BP 257 EP 266 PG 10 WC Computer Science, Theory & Methods; Telecommunications SC Computer Science; Telecommunications GA BAP67 UT WOS:000223160600030 ER PT B AU Johnston, WE AF Johnston, WE BE Tzeng, NF TI The intersection of grids and networks: Where the rubber hits the road SO TENTH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS, PROCEEDINGS LA English DT Proceedings Paper CT 10th International Conference on Parallel and Distributed Systems (ICPADS 2004) CY JUL 07-09, 2004 CL Newport Beach, CA SP IEEE Comp Soc, TCPP, IEEE Comp Soc, TCDP C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Energy Sci Network, Berkeley, CA 94720 USA. RP Johnston, WE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Energy Sci Network, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2152-5 PY 2004 BP 277 EP 277 PG 1 WC Computer Science, Theory & Methods; Telecommunications SC Computer Science; Telecommunications GA BAP67 UT WOS:000223160600032 ER PT B AU Siebers, DL Pickett, LM AF Siebers, DL Pickett, LM BE Whitelaw, JH Payri, F Arcoumanis, C Desantes, JM TI Injection pressure and orifice diameter effects on soot in DI diesel fuel jets SO THERMO- AND FLUID DYNAMIC PROCESSES IN DIESEL ENGINES 2 LA English DT Proceedings Paper CT Thiesel 2002 Conference on Thermo - and Fluid Dynamic Processes in Diesel Engines CY SEP 11-13, 2002 CL Valencia, SPAIN SP Univ Politen Valencia, Inst Transporte & Mat Movil, CMT Motores Termicos, Minist Ciencia & Tecnologia, ASEPA ID FLAMES AB The effects of injection pressure and orifice diameter on soot in diesel fuel jets were investigated under quiescent, direct-injection (DI) diesel engine conditions. These investigations were carried out in a constant-volume combustion vessel with complete optical access. The injector used was an electronically-control led, common-rail injector. Injection pressures between 40 MPa and 190 MPa and orifice diameters between 50 mum and 180 pm were considered. Soot was measured with a line-of-sight laser extinction technique and visualized with planar laser-induced incandescence. Flame lift-off lengths used in the analysis of the soot measurements were determined with time-averaged OH chemiluminescence imaging. The results show that the peak soot in a fuel jet decreases with increasing injection pressure and decreasing orifice diameter. The decrease in soot with increasing injection pressure was linear with increasing injection velocity (i.e., the square-root of the pressure drop across the injector orifice). The decrease in soot with decreasing orifice diameter was such that for the smallest orifice diameter considered (50 mum), no soot was detectable for the ambient gas and injector conditions considered. These direct measurements of soot within a fuel jet, coupled with estimates of the amount of air entrained relative to the amount of fuel injected, confirm that air entrainment and fuel-air mixing upstream of the lift-off length have an important role in determining the soot levels within a diesel fuel jet. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. RP Siebers, DL (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. NR 38 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-20187-4 PY 2004 BP 109 EP 132 PG 24 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA BY84M UT WOS:000189476800007 ER PT B AU Miles, PC Megerle, M Nagel, Z Liu, Y Reitz, RD Lai, MC Sick, V AF Miles, PC Megerle, M Nagel, Z Liu, Y Reitz, RD Lai, MC Sick, V BE Whitelaw, JH Payri, F Arcoumanis, C Desantes, JM TI The influence of swirl and injection pressure on post-combustion turbulence in a HSDI diesel engine SO THERMO- AND FLUID DYNAMIC PROCESSES IN DIESEL ENGINES 2 LA English DT Proceedings Paper CT Thiesel 2002 Conference on Thermo - and Fluid Dynamic Processes in Diesel Engines CY SEP 11-13, 2002 CL Valencia, SPAIN SP Univ Politen Valencia, Inst Transporte & Mat Movil, CMT Motores Termicos, Minist Ciencia & Tecnologia, ASEPA AB The effect of variable flow swirl and injection pressure on the generation of post-combustion turbulence is investigated in a HSDI diesel engine operating at a simulated idle condition. The engine is operated in three modes: motored, injected (fuel injected into a N-2 environment), and fired. The radial and tangential components of flow velocity are measured simultaneously for each operating condition. Radial and tangential gradients in the mean velocities are also measured, which, with the variance of the individual velocity components and the Reynolds stress, allow turbulence production due to r-theta plane fluid motion to be evaluated. Through comparison of the temporal evolution of turbulent kinetic energy k for the three operating conditions, the influence of the fuel injection event and the subsequent combustion is assessed, as is the influence of variable flow swirl and injection pressure. The turbulence production is investigated in detail for injected engine operation, where the complicating effects of combustion induced turbulence and large density variations are eliminated. The measured production and the evolution of the numerically predicted mean flow structures are evaluated for consistency with a simple picture wherein the fuel injection process redistributes the angular momentum of the swirling flow, creating an unstable flow that significantly enhances the flow turbulence. The simple picture is consistent with the majority of the trends in the data, and provides a mental model that is useful for understanding the effects of varying flow swirl, combustion chamber geometry, and fuel injection parameters. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Miles, PC (reprint author), Sandia Natl Labs, Combust Res Facil, POB 969, Livermore, CA 94551 USA. RI Sick, Volker/A-3987-2008 OI Sick, Volker/0000-0001-5756-9714 NR 12 TC 0 Z9 0 U1 0 U2 2 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY BN 3-540-20187-4 PY 2004 BP 133 EP 160 PG 28 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA BY84M UT WOS:000189476800008 ER PT S AU Wanlass, MW Ahrenkiel, SP Ahrenkiel, RK Carapella, JJ Wehrer, RJ Wernsman, B AF Wanlass, MW Ahrenkiel, SP Ahrenkiel, RK Carapella, JJ Wehrer, RJ Wernsman, B BE Gopinath, A Coutts, TJ Luther, J TI Recent advances in low-bandgap, InP-based GaInAs/InAsP materials and devices for thermophotovoltaic (TPV) energy conversion SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th International Conference on Thermophotovoltaic Generation of Electricity CY JUN 14-16, 2004 CL Freiburg, GERMANY SP Naval Sea Syst Command, NASA Glenn Res Ctr, USN Off Naval Res Int Field Off, UK, Natl Renewable Energy Lab, Fraunhofer Inst Solar Energy Syst ISE, Aixtron AG, Akzo Nobel, Wafer Technol Ltd, Epichem Grp AB Salient advances in the development of thermophotovoltaic (TPV) energy converters based on low-bandgap, InP-based, GaInAs/InAsP heterostructures are presented and discussed. InP-based materials are well-suited and advantageous for TPV converter applications. Substantial improvements in the quality of lattice-mismatched (LMM) heterostructures have been realized through an enhanced understanding of the relaxation behavior, and associated microstructure, of InAsP compositionally graded layers and GaInAs/InAsP interfaces. Double-heterostructure, GaInAs/InAsP test structures with bandgaps as low as 0.5 eV (1.6% lattice mismatch) have been demonstrated with exceptional low-injection, minority-carrier lifetimes (several mus) and large estimated diffusion lengths - comparable to those for lattice-matched materials. The advances in material quality have contributed to a number of notable TPV device achievements. A record in-cavity efficiency of 23.6% was reported for a 0.6-eV, GaInAs/InAsP monolithic interconnected module. Additionally, 0.52-eV GaInAs/InAsP TPV converters were demonstrated with near-unity internal quantum efficiencies and reverse-saturation current densities nearly equaling the best reported for lattice-matched, 0.52-eV GaInAsSb/GaSb devices. Furthermore, InP-based, 0.74/0.63-eV, monolithic, series-connected, tandem TPV converters are also under development and show promising performance; an in-cavity efficiency of 11% has been reported for preliminary devices. C1 NREL, Golden, CO USA. RP Wanlass, MW (reprint author), NREL, 1617 Cole Blvd, Golden, CO USA. NR 14 TC 7 Z9 7 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0222-1 J9 AIP CONF PROC PY 2004 VL 738 BP 427 EP 435 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BBM16 UT WOS:000226110600048 ER PT S AU Wanlass, MW Albin, DS AF Wanlass, MW Albin, DS BE Gopinath, A Coutts, TJ Luther, J TI A rigorous analysis of series-connected, multi-bandgap, tandem thermophotovoltaic (TPV) energy converters SO THERMOPHOTOVOLTAIC GENERATION OF ELECTRICITY SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 6th International Conference on Thermophotovoltaic Generation of Electricity CY JUN 14-16, 2004 CL Freiburg, GERMANY SP Naval Sea Syst Command, NASA Glenn Res Ctr, USN Off Naval Res Int Field Off, UK, Natl Renewable Energy Lab, Fraunhofer Inst Solar Energy Syst ISE, Aixtron AG, Akzo Nobel, Wafer Technol Ltd, Epichem Grp AB Multi-bandgap, photonic energy conversion is under investigation for nearly every class of photovoltaic materials, with monolithic, series-connected device structures being the preferred mode of implementation. For TPV energy conversion systems, such an approach represents the next wave in TPV converter advancement. In this paper, we focus on a rigorous analysis of series-connected, multi-bandgap, tandem (SCMBT) converter structures according to Kirchhoffs circuit laws. A general formulation is presented, followed by an application of the general formulation to a typical, semi-realistic model for well-behaved, p-n junction, photovoltaic devices. Using results generated from a computer code written in Visual Basic, we then present example calculations for SCMBT TPV converters with two subcells, for a TPV system utilizing a blackbody radiator operating at 954degreesC (1750degreesF). A comparison of the results obtained using the rigorous analysis, with those obtained by using the commonly adopted subcell-photocurrent-matching design rule, is discussed in detail. An output power density increase of similar to 5% is realized in the solution determined by the rigorous analysis, as compared to that obtained with the subcell-photocurrent-matching rule. Additional interesting, non-intuitive results are also highlighted. C1 NREL, Golden, CO USA. RP Wanlass, MW (reprint author), NREL, 1617 Cole Blvd, Golden, CO USA. NR 11 TC 13 Z9 13 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0222-1 J9 AIP CONF PROC PY 2004 VL 738 BP 462 EP 470 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BBM16 UT WOS:000226110600052 ER PT S AU Wang, H Wade, DR Kam, J AF Wang, H Wade, DR Kam, J BE Burleigh, DD Cramer, KE Peacock, GR TI IR imaging of blood circulation of patients with vascular disease SO THERMOSENSE XXVI SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Thermosense XXVI CY APR 13-15, 2004 CL Orlando, FL SP SPIE DE IR imaging; vascular disease ID SKIN-TEMPERATURE; BREAST-CANCER; THERMOGRAPHY; FLOW; SYSTEM; TUMORS; TIME; BODY; HAND AB We conducted a preliminary IR imaging study of blood circulation in patients with peripheral vascular diseases. Abnormal blood flow is common in older adults, especially those with elevated blood lipids, diabetes, hypertension, and a history of smoking. All of these conditions have a high prevalence in our population, often with more than one condition in the same individual. The differences in blood flow is revealed by temperature differences in areas of the extremities as well as other regions of the body. However, what is needed is an imaging technique that is relatively inexpensive and can reveal the blood flow in real time. The IR imaging can show detailed venous system and small tempearture changes associated with blood flow. Six patients with vascular diseases were tested in a clinic set up. Their legs and feet were imaged. We observed large temperature differences (cooling of more than 10degrees C) at the foot, especially toes. More valuable information were obtained from the temperature distribution maps. IR thermography is potentially a very valuable tool for medical application, especially for vascular diseases. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Bldg 4515 MS-6064, Oak Ridge, TN 37831 USA. RI Wang, Hsin/A-1942-2013; OI Wang, Hsin/0000-0003-2426-9867; Li, Xiaoying/0000-0001-6449-1505 NR 29 TC 6 Z9 6 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5328-5 J9 PROC SPIE PY 2004 VL 5405 BP 115 EP 123 DI 10.1117/12.545899 PG 9 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BAL28 UT WOS:000222663600013 ER PT S AU Burke, MW Miller, WO AF Burke, MW Miller, WO BE Burleigh, DD Cramer, KE Peacock, GR TI Status of VibroIR at Lawrence Livermore National Laboratory SO THERMOSENSE XXVI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Thermosense XXVI CY APR 13-15, 2004 CL Orlando, FL SP SPIE DE nondestructive evaluation; infrared imaging; vibrothermography; thermography; brazed joints; composites AB Current efforts at Lawrence Livermore National Laboratory in the area of vibrothermography (VibroIR or SonicIR) are presented. The primary goals of the efforts of the NDE group at LLNL have been to demonstrate the applicability of vibrothermography to new areas, to examine the degree to which VibroIR may replace existing NDE inspection procedures, and to conduct research on the underlying processes and optimal parameters in its implementation. We report three new applications of VibroIR, in the areas of brazed tube Joint inspection, evaluationtion of thick multilayer carbon/carbon composites as used in the NASA Shuttle, and the inspection of soft composite materials. The goal of the brazed joint inspection process is ultimately the replacement of a current dye penetrant inspection procedure. Therefore a direct comparison between VibroIR and dye penetrant inspection is made. Preliminary results of the analysis of a leading edge panel from a NASA Shuttle is also reported as an example of the application of VibroIR to thick composites. Finally, a comparison betweeen the effectiveness of VibroIR versus a spectrum of other NDE techniques (ultrasonic imaging, radiographic tomography) for the imaging of known ceramic defects is briefly discussed. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Burke, MW (reprint author), Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. NR 0 TC 14 Z9 15 U1 2 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5328-5 J9 P SOC PHOTO-OPT INS PY 2004 VL 5405 BP 313 EP 321 DI 10.1117/12.544895 PG 9 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BAL28 UT WOS:000222663600036 ER PT S AU Wang, H Feng, ZL Sklad, PS AF Wang, H Feng, ZL Sklad, PS BE Burleigh, DD Cramer, KE Peacock, GR TI Inspection and evaluation of laser welds for transit buses SO THERMOSENSE XXVI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Thermosense XXVI CY APR 13-15, 2004 CL Orlando, FL SP SPIE DE IR imaging; laser welding; non-destructive AB Laser welds in light-weight transit bus panels were studied by IR imaging. The corrugated structural panels were made from 3 mm thick stainless steel. The panels were welded by a high power laser with lines of equally spaced 1" stitches. After discovering problems by visual and tapping inspections, the panels were sent to our laboratory for further investigation. The IR thermography method was chosen to study the welds because of its non-contact nature and potential for large area, high-speed inspections. We used thermophysical properties of the panels and finite element modeling to predict temperature variations of "good" and "bad" welds. Surface heating and "heat leak" methods were used to inspect each weld. The IR images clearly showed characteristic temperature signatures of "good" and "bad" welds. We also discovered a number of partial welds and questionable welds. In the follow-up destructive inspection, the welds interfaces were imaged and related to the infrared images. No or partial penetration were found on a number of bad and partial welds. Even in the good welds, the weld stitch appeared to be discontinuous. This study helped the bus manufacturer to assess their welding process and make necessary improvement. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wang, H (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Feng, Zhili/H-9382-2012; Wang, Hsin/A-1942-2013 OI Feng, Zhili/0000-0001-6573-7933; Wang, Hsin/0000-0003-2426-9867 NR 8 TC 1 Z9 1 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5328-5 J9 P SOC PHOTO-OPT INS PY 2004 VL 5405 BP 382 EP 389 DI 10.1117/12.543920 PG 8 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BAL28 UT WOS:000222663600044 ER PT S AU Tang, MJ Xu, GS Cai, W Bulatov, V AF Tang, MJ Xu, GS Cai, W Bulatov, V BE Corcoran, SG Joo, YC Moody, NR Suo, Z TI Dislocation image stresses at free surfaces by the finite element method SO THIN FILMS-STRESSES AND MECHANICAL PROPERTIES X SE MATERIALS RESEARCH SOCIETY SYMPOSIUM PROCEEDINGS LA English DT Proceedings Paper CT Symposium on Thin Films - Stresses and Mechanical Properties X held at the 2003 MRS Fall Meeting CY DEC 01-05, 2003 CL Boston, MA SP Mat Res Soc, Adv Micro Devices Inc, Hysitron Inc, MTS Syst Corp ID SINGLE-CRYSTALS; DYNAMICS; PLASTICITY AB The finite element method has been routinely used to calculate the image stresses of dislocation segments. When these segments intersect with surfaces, the image stresses at the surfaces diverge singularly. At the presence of these singularities, both convergence and accuracy of using the finite element method need to be examined critically. This article addresses these issues with the aim toward the application of dislocation dynamics simulations in thin films. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Tang, MJ (reprint author), Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 10 TC 1 Z9 1 U1 0 U2 2 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DRIVE, WARRENDALE, PA 15088-7563 USA SN 0272-9172 BN 1-55899-733-4 J9 MATER RES SOC SYMP P PY 2004 VL 795 BP 29 EP 33 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Coatings & Films; Physics, Condensed Matter SC Materials Science; Physics GA BY87L UT WOS:000189484000005 ER PT J AU Jeong, BS Norton, DP Budai, JD Jellison, GE AF Jeong, BS Norton, DP Budai, JD Jellison, GE TI Epitaxial growth of anatase by reactive sputter deposition using water vapor as the oxidant SO THIN SOLID FILMS LA English DT Article DE epitaxy; oxides; semiconductors; titanium oxide ID TIO2 THIN-FILMS; OPTICAL-PROPERTIES; TITANIUM-DIOXIDE; SINGLE-CRYSTALS; TEMPERATURE; SUBSTRATE; SURFACES; RUTILE; LAALO3; VACUUM AB The growth of TiO2 films in the anatase crystal structure was investigated using reactive sputter deposition with H2O serving as the oxidizing species. With water vapor, the formation of phase-pure anatase TiO2 thin films via epitaxial stabilization on (001) LaAlO3 was achieved, although crystallinity was slightly inferior to that obtained when O-2 was employed. Films grown using water vapor exhibited a rougher surface morphology indicating a difference in growth mechanisms. At low H2O pressure, the formation of a TinO2n-1 Magneli phase was observed. When hydrogen was employed during growth, mixed phase films of rutile and anatase resulted. The development of crystallinity and phase as a function of deposition temperature and oxidant pressure are discussed. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Univ Florida, Dept Mat Sci & Engn, 106 Rhines Hall, Gainesville, FL 32611 USA. EM dnort@mse.ufl.edu RI Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 37 TC 17 Z9 17 U1 3 U2 12 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 1 PY 2004 VL 446 IS 1 BP 18 EP 22 DI 10.1016/S0040-6090(03)01238-0 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 759AX UT WOS:000187716300004 ER PT J AU Stearns, DG Mirkarimi, PB Spiller, E AF Stearns, DG Mirkarimi, PB Spiller, E TI Localized defects in multilayer coatings SO THIN SOLID FILMS LA English DT Article DE non-linear continuum model; localized defects; Mo/Si multilayer coating ID EXTREME-ULTRAVIOLET LITHOGRAPHY; THIN-FILMS; PROJECTION LITHOGRAPHY; ELECTRON-MICROSCOPY; OPTICAL COATINGS; GOLD NANOSPHERES; NODULAR GROWTH; MASKS; SIMULATION; MICROSTRUCTURE AB We present a non-linear continuum model of the growth of localized defects in multilayer coatings nucleated by particles on the substrate. The model is valid when the deposition and etch fluxes are near normal incidence so that shadowing effects are negligible. Three-dimensional simulations of defects in Mo/Si multilayer films nucleated by arrays of lithographically patterned particles are shown to be in good agreement with experimental measurements. Our results confirm that incorporating ion beam etching in the multilayer deposition process significantly suppresses the defect growth. This has a potentially important application in the fabrication of defect-free masks for extreme ultraviolet lithography. (C) 2003 Elsevier B.V. All rights reserved. C1 OS Associates, Mountain View, CA 94040 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Spillar Xray Opt, Livermore, CA 94551 USA. RP Stearns, DG (reprint author), OS Associates, 1174 Castro St,Suite 250, Mountain View, CA 94040 USA. NR 37 TC 47 Z9 52 U1 1 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JAN 1 PY 2004 VL 446 IS 1 BP 37 EP 49 DI 10.1016/S0040-6090(03)01285-9 PG 13 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 759AX UT WOS:000187716300007 ER PT B AU Fisher, K Kimmerer, W AF Fisher, K Kimmerer, W BE Novak, MM TI Fractal distributions of temperature, salinity and fluorescence in spring 2001-2002 in South San Francisco Bay SO THINKING IN PATTERNS: FRACTALS AND RELATED PHENOMENA IN NATURE LA English DT Proceedings Paper CT 8th International Conference on Thinking in Patterns -Fractals and Related Phenomena in Nature CY APR 04-07, 2004 CL Vancouver, CANADA ID GOVERNING PHYTOPLANKTON BLOOMS; ESTUARIES; BIOMASS; DYNAMICS; PRODUCTIVITY; TRANSPORT; USA AB In this paper, we demonstrate a wavelet-based analysis of the changing fractal character of temperature, salinity, and fluorescence distributions in South San Francisco Bay. In particular, we are interested in comparing the fractal character of the physical and biological elements of the system. This analysis indicates that the system exhibits two distinct states; one in which physical (salinity and temperature) and biological (fluorescence) variables show similar fractal character across scales of 120 meters to 2 kilometers, and one in which fluorescence shows substantially different character than the others. These regimes occur in spring seasons with an episodic fluorescence structure (2002), and a more consistent seasonal structure (2001) respectively. During spring of 2001 fluorescence has somewhat higher persistence than the physical variables. During spring of 2002, the physical and biological variables have similar persistence. Differences in the response of fluorescence to physical variables may reflect differences in the pattern of stratification and bloom development during these years. Analysis of the fractal character of these signals offers a promising approach to assessing and adequately modeling the patchiness of biological distributions at scales of meters to kilometers in rapidly fluctuating dynamic systems. Realistic patchiness can then be used in models of the system, leading to better characterization of biological and physical coupling across a wide range of scales. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Fisher, K (reprint author), Los Alamos Natl Lab, POB 1663,MS B296, Los Alamos, NM 87545 USA. EM kefisher@lanl.gov; kimmerer@sfsu.edu NR 26 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-238-822-2 PY 2004 BP 199 EP 211 DI 10.1142/9789812702746_0016 PG 13 WC Mathematics SC Mathematics GA BCM63 UT WOS:000230001300016 ER PT S AU Jinschek, JR Kisielowski, C Van Dyck, D Geuens, P AF Jinschek, JR Kisielowski, C Van Dyck, D Geuens, P BE Ferguson, IT Narendran, N DenBaars, SP Carrano, JC TI Measurement of the indium segregation in InGaN based LEDs with single atom sensitivity SO THIRD INTERNATIONAL CONFERENCE ON SOLID STATE LIGHTING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd International Conference on Solid State Lighting CY AUG 05-07, 2003 CL San Diego, CA SP SPIE DE indium gallium nitride (InGaN); gallium nitride (GaN); quantum well; indium (In) distribution/segregation; transmission electron microscopy; HRTEM; phase contrast; exit wave reconstruction (EWR) ID TRANSMISSION ELECTRON-MICROSCOPY; THIN-FILMS; RECONSTRUCTION; RESOLUTION; DIFFRACTION; CRYSTALS; HRTEM AB In light emitting diodes (LED) consisting of GaN / InGaN / GaN quantum wells (QWs), the exact indium distribution inside the wells of the active region affects the performance of devices. Indium segregation can take place forming small InGaN clusters of locally varying composition. In the past, we used a local strain analysis from single HRTEM lattice images to determine the In composition inside the InGaN QWs with a resolution of 0.5 nm x 0.3 nm. Truly atomic resolution can be pursued by exploitation of intensity dependencies on the atomic number (Z) of the electron exit-wave (EW). In microscopes with sufficient sensitivity, local variations of amplitude and phase are found to be discrete with sample thickness, which allows for counting the number of atoms in each individual column of similar to 0.08 nm diameter. In QW's of similar to 17% of average indium concentration it is possible to discriminate between pure Ga columns and columns containing 1, 2, 3, or more In atoms because phase changes are discrete and element specific. The preparation of samples with atomically flat surfaces is a limiting factor for the application of the procedure. C1 Univ Calif Berkeley, NCEM, LBNL, Berkeley, CA 94720 USA. RP Jinschek, JR (reprint author), Univ Calif Berkeley, NCEM, LBNL, 1 Cyclotron Rd,MS R720150, Berkeley, CA 94720 USA. NR 28 TC 14 Z9 14 U1 0 U2 7 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5060-X J9 P SOC PHOTO-OPT INS PY 2004 VL 5187 BP 54 EP 63 DI 10.1117/12.513121 PG 10 WC Optics; Physics, Condensed Matter SC Optics; Physics GA BY61M UT WOS:000189421600006 ER PT S AU Gee, JM Tsao, JY Simmons, JA AF Gee, JM Tsao, JY Simmons, JA BE Ferguson, IT Narendran, N DenBaars, SP Carrano, JC TI Prospects for LED lighting SO THIRD INTERNATIONAL CONFERENCE ON SOLID STATE LIGHTING SE Proceedings of SPIE-The International Society for Optical Engineering LA English DT Proceedings Paper CT 3rd International Conference on Solid State Lighting CY AUG 05-07, 2003 CL San Diego, CA SP SPIE AB Solid-state lighting using light-emitting diodes (LEDs) has the potential to reduce energy consumption for lighting by 50% while revolutionizing the way we illuminate our homes, work places, and public spaces. Nevertheless, substantial technical challenges remain in order for solid-state lighting to significantly displace the well-developed conventional lighting technologies. We review the potential of LED solid-state lighting to meet the long-term cost goals. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Gee, JM (reprint author), Sandia Natl Labs, Albuquerque, NM 87185 USA. EM jmgee@sandia.gov NR 10 TC 6 Z9 7 U1 1 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5060-X J9 P SOC PHOTO-OPT INS PY 2004 VL 5187 BP 227 EP 233 DI 10.1117/12.504813 PG 7 WC Optics; Physics, Condensed Matter SC Optics; Physics GA BY61M UT WOS:000189421600025 ER PT S AU Borbely, A Johnson, SG AF Borbely, A Johnson, SG BE Ferguson, IT Narendran, N DenBaars, SP Carrano, JC TI Prediction of light extraction efficiency of LEDs by ray trace simulation SO THIRD INTERNATIONAL CONFERENCE ON SOLID STATE LIGHTING SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 3rd International Conference on Solid State Lighting CY AUG 05-07, 2003 CL San Diego, CA SP SPIE DE LED; light extraction efficiency; ray trace simulation; solid model AB The advantage of enhancing the light extraction of LED dies is twofold: it increases the overall efficiency of the device, reducing internal absorption and subsequently the temperature of the device. We have developed the solid model of a commercially available blue LED in a ray tracing simulation software according to the physical structure of the GaN die grown on SiC substrate. Optical parameters of the various device layers were adjusted within a plausible range to achieve the best match between the measured and the simulated spatial luminous intensity profile. Two approaches for improving the light extraction efficiency were examined using the model: change of refractive index of the encapsulating medium and chip shaping. Simulation results were verified by a series of luminous intensity and total flux measurements in a mini-goniophotometer. We found that the physical experiment confirmed the predicted results. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Borbely, A (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 5 TC 6 Z9 6 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5060-X J9 P SOC PHOTO-OPT INS PY 2004 VL 5187 BP 301 EP 308 DI 10.1117/12.504935 PG 8 WC Optics; Physics, Condensed Matter SC Optics; Physics GA BY61M UT WOS:000189421600034 ER PT B AU Galassi, M Borozdin, K Casperson, D McGowan, K Starr, D White, R Wozniak, P Wren, J AF Galassi, M Borozdin, K Casperson, D McGowan, K Starr, D White, R Wozniak, P Wren, J BE Feroci, M Frontera, F Masetti, N Piro, L TI Raptor - Mining the sky in real time SO THIRD ROME WORKSHOP ON GAMMA-RAY BURSTS IN THE AFTERGLOW ERA SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT 3rd Workshop on Gamma-Ray Bursts CY SEP 17-20, 2002 CL CNR, Rome, ITALY HO CNR AB The primary goal of Raptor is ambitious: to identify interesting optical transients from very wide field of view telescopes in real time, and then to quickly point the higher resolution Raptor "fovea" cameras and spectrometer to the location of the optical transient. The most interesting of Raptor's many applications is the real-time search for orphan optical counterparts of Gamma Ray Bursts. The sequence of steps (data acquisition, basic calibration, source extraction, astrometry, relative photometry, the smarts of transient identification and elimination of false positives, telescope pointing feedback...) is implemented with a "component" aproach. All basic elements of the pipeline functionality have been written from scratch or adapted (as in the case of SExtractor for source extraction) to form a consistent modern API operating on memory resident images and source lists. The result is a pipeline which meets our real-time requirements and which can easily operate as a monolithic or distributed processing system. Finally: the Raptor architecture is entirely based on free software (sometimes referred to as "open source" software). In this paper we also discuss the interplay between various free software technologies in this type of astronomical problem. C1 Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87544 USA. RP Galassi, M (reprint author), Los Alamos Natl Lab, Space & Remote Sensing Sci Grp, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-165-6 J9 ASTR SOC P PY 2004 VL 312 BP 524 EP 527 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAM85 UT WOS:000222873300110 ER PT B AU Moller, P Sierk, AJ Ichikawa, T Iwamoto, A AF Moller, P Sierk, AJ Ichikawa, T Iwamoto, A BE Arnould, M Lewitowicz, M Munzenberg, G Akimune, H Ohta, M Utsunomiya, H Wada, T Yamagata, T TI Calculation of high-dimensional fission-fusion potential-energy surfaces in the SHE region SO TOURS SYMPOSIUM ON NUCLEAR PHYSICS V LA English DT Proceedings Paper CT Tours Symposium on Nuclear Physics V CY AUG 26-29, 2003 CL Tours, FRANCE SP Konan Univ, Council Gen Indre Loire, GANIL, GSI, Univ Francois Rabelais, Lycee Coll Konan Touraine ID GROUND-STATE MASSES; DEFORMATIONS; SYSTEMATICS; COLLISIONS; NUCLEI AB We calculate in a macroscopic-microscopic model fission-fusion potential-energy surfaces relevant to the analysis of heavy-ion reactions employed to form heavy-element evaporation residues. We study these multidimensional potential-energy surfaces both inside and outside the touching point. Inside the point of contact we define the potential on a multi-million-point grid in 5D deformation space where elongation, merging projectile and target spheroidal shapes, neck radius and projectile/target mass asymmetry are independent shape variables. The same deformation space and the corresponding potential-energy surface also describe the shape evolution from the nuclear ground-state to separating fragments in fission, and the fast-fission trajectories in incomplete fusion. For separated nuclei we study the macroscopic-microscopic potential energy, that is the "collision surface" between a spheroidally deformed target and a spheroidally deformed projectile as a function of three coordinates which are: the relative location of the projectile center-of-mass with respect to the target center-of-mass and the spheroidal deformations of the target and the projectile. We limit our study to the most favorable relative positions of target and projectile, namely that the symmetry axes of the target and projectile are collinear. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Moller, P (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. NR 15 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA BN 0-7354-0177-2 PY 2004 BP 49 EP 59 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear SC Astronomy & Astrophysics; Physics GA BAA54 UT WOS:000221351300006 ER PT J AU Fritz, JS AF Fritz, JS TI Ion pairing adapts HPLC columns to IC SO TRAC-TRENDS IN ANALYTICAL CHEMISTRY LA English DT News Item C1 Iowa State Univ, Ames Lab, Ames, IA USA. RP Fritz, JS (reprint author), Iowa State Univ, Ames Lab, Ames, IA USA. EM kniss@ameslab.gov NR 1 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 0165-9936 J9 TRAC-TREND ANAL CHEM JI Trac-Trends Anal. Chem. PD JAN PY 2004 VL 23 IS 1 BP IV EP IV PG 1 WC Chemistry, Analytical SC Chemistry GA 768ZH UT WOS:000188601100002 ER PT S AU Southworth, F Vogt, DP Curlee, TR AF Southworth, F Vogt, DP Curlee, TR GP TRB TI Estimation of statewide urban public transit benefits in Tennessee SO TRANSIT PLANNING AND DEVELOPMENT, MANAGEMENT AND PERFORMANCE, MARKETING AND FARE POLICY, AND CAPACITY AND QUALITY OF SERVICE SE TRANSPORTATION RESEARCH RECORD LA English DT Article; Proceedings Paper CT 83rd Annual Meeting of the Transportation-Research-Board CY JAN 11-15, 2004 CL Washington, DC SP Transportat Res Board, US Dept Transportat, US Bur Transportat Stat, US Fed Aviat Adm, US Fed Highway Adm, US Fed Motor Carrier Safety Adm, US Fed Railroad Adm, US FedTransit Adm, US Natl Highway Traff Safety Adm, US Res& Special Programs Adm, NASA, USA Corps Engineers, US Coast Guard, US DOE, US EPA AB A comprehensive transit benefits assessment procedure is described as applied to each of the 12 urban public transit operating districts in the state of Tennessee. A multiple-branch benefits assessment tree is developed around transit use benefits and transit supply benefits, the former emphasizing the costs of lost mobility in the absence of current transit services and the latter reflecting the economic benefits resulting from federal and state support for public transit in each district. Empirical results are presented at the statewide level and in dollar terms. With a generally conservative approach to benefits estimation, it is found that urban transit benefits-mainly from fixed-route bus service-exceed costs by 2 to 2.5 times, with higher ratios possible in the larger metropolitan areas. Sensitivity to forgone travel benefits, however, suggests the need for further data refinements. On the basis of past literature, the study develops a comprehensive set of wide-ranging benefits computations that have been applied consistently across each of the state's 12 urban transit districts and uses data sources that can be cost-effectively updated by transit planners. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Southworth, F (reprint author), Bldg NTRC,MS-6472,2360 Cherahala Blvd, Knoxville, TN 37932 USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU TRANSPORTATION RESEARCH BOARD NATL RESEARCH COUNCIL PI WASHINGTON PA 500 FIFTH ST, NW, WASHINGTON, DC 20001 USA SN 0361-1981 BN 0-309-09482-8 J9 TRANSPORT RES REC PY 2004 IS 1887 BP 83 EP 91 PG 3 WC Engineering, Civil; Transportation; Transportation Science & Technology SC Engineering; Transportation GA BBR03 UT WOS:000227335100010 ER PT S AU Stojanoff, V Cappelle, B Epelboin, Y Hartwig, J Moradela, AB Otalora, F AF Stojanoff, V Cappelle, B Epelboin, Y Hartwig, J Moradela, AB Otalora, F BE Sadhal, SS TI High resolution imaging as a characterization tool for biological crystals SO TRANSPORT PHENOMENA IN MICROGRAVITY SE Annals of the New York Academy of Sciences LA English DT Article; Proceedings Paper CT Conference on Microgravity Transport Processes in Fluid, Thermal, Materials and Biological Sciences CY SEP 14-18, 2003 CL Davos, SWITZERLAND SP Engn Conf Int, NASA, US Natl Sci Fdn DE high resolution X-ray diffraction; biomolecular crystals ID X-RAY-DIFFRACTION; LYSOZYME CRYSTALS; PROTEIN CRYSTALS; SYNCHROTRON-RADIATION; TETRAGONAL LYSOZYME; TOPOGRAPHY; GROWTH; CRYSTALLIZATION; DISLOCATIONS; QUALITY AB Biomolecular crystals consist of large unit cells that form a rather flexible medium that is able to accommodate a certain degree of lattice distortion, leading to several interesting issues ranging from structural to physical properties. Several techniques, from X-ray diffraction to microscopy, have been adapted to study the structural and physical properties of biomolecular crystals systematically. The use of synchrotron-based monochromatic X-ray diffraction topography, with triple axis diffractometry and rocking curve measurements, to characterize biomolecular crystals is reviewed. Recent X-ray diffraction images from gel and solution grown lysozyme crystals are presented. Defect structures in these crystals are discussed, together with reciprocal space mapping, and compared with results obtained from crystals grown in a low gravity environment. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Univ Paris 06, CNRS, LMCP, UMR 7590, Paris, France. European Synchrotron Radiat Facil, BP 220, F-38043 Grenoble, France. IACT, LEC, Granada, Spain. RP Stojanoff, V (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. EM stojanof@bnl.gov RI stojanoff, vivian /I-7290-2012; Otalora, Fermin/L-5477-2015; Otalora, Femin/F-2759-2017 OI stojanoff, vivian /0000-0002-6650-512X; NR 26 TC 2 Z9 2 U1 0 U2 1 PU NEW YORK ACAD SCIENCES PI NEW YORK PA 2 EAST 63RD ST, NEW YORK, NY 10021 USA SN 0077-8923 BN 1-57331-563-X J9 ANN NY ACAD SCI JI Ann.NY Acad.Sci. PY 2004 VL 1027 BP 48 EP 55 DI 10.1196/annals.1324.005 PG 8 WC Biophysics; Mechanics; Multidisciplinary Sciences SC Biophysics; Mechanics; Science & Technology - Other Topics GA BBP91 UT WOS:000226975400005 PM 15644344 ER PT J AU Yarotski, DA Taylor, AJ AF Yarotski, DA Taylor, AJ TI Ultrafast scanning tunneling microscopy: Principles and applications SO ULTRAFAST DYNAMICAL PROCESSES IN SEMICONDUCTORS SE TOPICS IN APPLIED PHYSICS LA English DT Review ID PICOSECOND ELECTRICAL TRANSIENTS; INAS/GAAS QUANTUM DOTS; PROBE MICROSCOPY; TIME RESOLUTION; SEMICONDUCTOR SURFACES; ELECTRONIC-STRUCTURE; TEMPORAL RESOLUTION; CARRIER-RELAXATION; JUNCTION; TIP AB The growing field of nanotechnology requires special tools capable of probing ultrafast surface dynamics on atomic scales in order to unveil the fundamental relationships between material structure and its properties. The invention of the scanning tunneling microscope (STM) revolutionized the field of surface science, enabling the first images of surface structure on an atomic length scale. However, investigations using STM techniques have been largely restricted to the study of static surface properties such as electronic structure and topography, revealing little information on the dynamics underlying the phenomena under study. On the other hand, ultrafast optical techniques routinely reveal material dynamics on timescales as short as 10 fs, but with a spatial resolution > 1 mum. This chapter describes several approaches for combining these two techniques to measure ultrafast dynamics on an atomic scale. We describe here approaches for ultrafast STM based on photoconductive gating ultrafast STM, time-resolved STM through tunnel-distance modulation, and ultrafast junction-mixing STM. While much progress has been made to develop these techniques and understand both their limitations and exactly what each technique measures, we still have much to learn before ultrafast STM becomes a standard method for characterizing the dynamics on the nanoscale. C1 Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Yarotski, DA (reprint author), Los Alamos Natl Lab, Condensed Matter & Thermal Phys Grp, POB 1663, Los Alamos, NM 87545 USA. EM ttaylor@lanl.gov RI Yarotski, Dmitry/G-4568-2010 NR 66 TC 2 Z9 2 U1 3 U2 11 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0303-4216 J9 TOP APPL PHYS PY 2004 VL 92 BP 57 EP 97 PG 41 WC Physics, Applied SC Physics GA BY72Q UT WOS:000189448300002 ER PT S AU Htoon, H Shih, CK AF Htoon, H Shih, CK BE Tsen, KT TI Ultrafast coherent dynamics in semiconductor quantum dots SO ULTRAFAST DYNAMICAL PROCESSES IN SEMICONDUCTORS SE Topics in Applied Physics LA English DT Review ID SHARP-LINE PHOTOLUMINESCENCE; ENERGY-RELAXATION; CARRIER RELAXATION; MULTIPHONON PROCESSES; ELECTRONIC-STRUCTURE; OPTICAL-SPECTRA; AUGER PROCESSES; BOX SYSTEMS; STATES; SPECTROSCOPY AB In this chapter we will review the studies on ultrafast coherence phenomena of self-assembled semiconductor quantum dots (SAQDs). These studies provide the understanding required for the utilization of quantum dots as the fundamental building block of a solid-state quantum computer. We performed extensive studies on quantum-decoherence processes of excitons trapped in the various excited states of SAQDs. Energy-level structure and dephasing times of excited states were first determined by conducting photoluminescence-excitation spectroscopy and wavepacket interferometry on a large number of individual SAQDs. Major mechanisms responsible for the dephasing of various excited quantum states are determined through the systematic analysis of the correlation between dephasing times and energy-level structure of the (aDs. The studies revealed that the dephasing in some of the energetically isolated excited states was strongly suppressed due to the "phonon bottleneck" effect. These states with long dephasing times further provide opportunities to explore other fundamental quantum-coherent phenomena. We observed the direct experimental evidence of Rabi oscillation in these types of excited states. Furthermore, wavepacket-interferometry experiments performed on these states in the strong-excitation regime revealed a new type of quantum-interference phenomenon that emerged from the interplay between quantum interference and the nonlinear effect of Rabi oscillation. This phenomenon can be utilized as a coherent control mechanism where both phase and amplitude of a wavefunction can be manipulated simultaneously. C1 Univ Texas, Dept Phys, Austin, TX 78712 USA. RP Htoon, H (reprint author), Los Alamos Natl Lab, Div Chem, CPCS, MS J585, Los Alamos, NM 87544 USA. EM shih@physics.utexas.edu NR 79 TC 1 Z9 1 U1 1 U2 11 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0303-4216 BN 3-540-40239-X J9 TOP APPL PHYS JI Top. Appl. Phys. PY 2004 VL 92 BP 99 EP 137 PG 39 WC Physics, Applied SC Physics GA BY72Q UT WOS:000189448300003 ER PT J AU Cavalleri, A Schoenlein, RW AF Cavalleri, A Schoenlein, RW TI Femtosecond X-rays and structural dynamics in condensed matter SO ULTRAFAST DYNAMICAL PROCESSES IN SEMICONDUCTORS SE TOPICS IN APPLIED PHYSICS LA English DT Review ID PICOSECOND LIGHT-PULSES; LASER-PRODUCED PLASMAS; HARMONIC-GENERATION; AUGER RECOMBINATION; PHASE-TRANSITION; LATTICE-DYNAMICS; DIFFRACTION; GERMANIUM; ABSORPTION; SILICON AB In this chapter, some of the recent advancements in the nascent field of femtosecond X-ray scattering are reviewed. First, we discuss selected diffraction experiments performed with femtosecond pulses of K-alpha fluorescence from a TW-laser-generated Cu plasmas. Coherent acoustic phonons in both bulk and layered semiconductor heterostructures have been investigated. These experiments provide direct information on lattice motion well beyond the depths that are typically probed by visible light. Vibrational transport across buried interfaces, as well as dephasing of lattice waves have been directly measured and modeled. The same apparatus has been used to probe subpicosecond formation of a product structural phase during a photoinduced phase transition in the strongly correlated material VO2. Secondly, we review parallel progress in the generation of tunable femtosecond pulses from third-generation storage rings, achieved by interaction of femtosecond optical pulses and picosecond-long electron bunches within an insertion device (wiggler). The primary advantage of these new schemes, producing trains of pulses that are comparable in photon numbers to laser-produced plasma sources, is the tunability from the visible to the hard X-ray regime. We describe one possible application of these tunable femtosecond pulses to X-ray spectroscopies of transition metal oxides, where near-edge absorption (NEXAFS) and extended X-ray absorption (EXAFS) can probe electronic, magnetic, and short-range atomic structure during a phase transition. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Cavalleri, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM acavalleri@lbl.gov RI Schoenlein, Robert/D-1301-2014 OI Schoenlein, Robert/0000-0002-6066-7566 NR 61 TC 9 Z9 9 U1 4 U2 9 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 0303-4216 J9 TOP APPL PHYS PY 2004 VL 92 BP 309 EP 337 PG 29 WC Physics, Applied SC Physics GA BY72Q UT WOS:000189448300007 ER PT S AU Toth, C Faure, J van Tilborg, J Geddes, CGR Schroeder, CB Esarey, E Leemans, WP AF Toth, C Faure, J van Tilborg, J Geddes, CGR Schroeder, CB Esarey, E Leemans, WP BE Krausz, F Korn, G Corkum, P Walmsley, IA TI Asymmetric pulse shapes in grating-based CPA compressors and optimal electron acceleration in plasmas SO ULTRAFAST OPTICS IV SE Springer Series in Optical Sciences LA English DT Proceedings Paper CT 4th International Conference on Ultrafast Optics CY JUN, 2003 CL Vienna, AUSTRIA ID OPTICAL PULSES; PHASE-CONTROL; LASER; AMPLIFICATION; AMPLITUDE; SYSTEMS AB The temporal shape (skew) of the envelope function of 50-200 femtosecond Ti:sapphire laser pulses has been controlled by fine-tuning the higher-order spectral phase coefficients to optimize the electron yield of a self-modulated plasma wake-field accelerator. C1 Lawrence Berkeley Natl Lab, LOASIS Grp, Ctr Beam Phys, Berkeley, CA 94720 USA. RP Lawrence Berkeley Natl Lab, LOASIS Grp, Ctr Beam Phys, BLDG 71R0259,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM ctoth@lbl.gov NR 15 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES SN 0342-4111 BN 0-387-40091-5 J9 SPRINGER SER OPT SCI PY 2004 VL 95 BP 349 EP 354 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA BAG72 UT WOS:000222127000045 ER PT S AU Jovanovic, I Schmidt, JR Ebbers, CA AF Jovanovic, I Schmidt, JR Ebbers, CA BE Krausz, F Korn, G Corkum, P Walmsley, IA TI Optical parametric chirped-pulse amplification in periodically-poled KTiOPO(4) at 1053 nm SO ULTRAFAST OPTICS IV SE Springer Series in Optical Sciences LA English DT Proceedings Paper CT 4th International Conference on Ultrafast Optics CY JUN, 2003 CL Vienna, AUSTRIA ID 2ND-HARMONIC GENERATION; LITHIUM-NIOBATE; COMPRESSION; AMPLIFIERS C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Jovanovic, I (reprint author), Lawrence Livermore Natl Lab, Mail Code L-490,7000 East Ave, Livermore, CA 94550 USA. EM jovanovic1@llnl.gov NR 12 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013, UNITED STATES SN 0342-4111 BN 0-387-40091-5 J9 SPRINGER SER OPT SCI PY 2004 VL 95 BP 367 EP 372 PG 6 WC Optics; Physics, Applied SC Optics; Physics GA BAG72 UT WOS:000222127000047 ER PT B AU Liao, XZ Zhao, YH Srinivasan, SG Zhou, F Lavernia, EJ Baskes, MI Xu, HF Valiev, RZ Zhu, YT AF Liao, XZ Zhao, YH Srinivasan, SG Zhou, F Lavernia, EJ Baskes, MI Xu, HF Valiev, RZ Zhu, YT BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Stacking fault and twinning in nanocrystalline metals SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm DE nanocrystalline; aluminum; copper; deformation mechanisms; twinning; stacking faults ID MOLECULAR-DYNAMICS SIMULATION; SEVERE PLASTIC-DEFORMATION; FLOW-STRESS; GRAIN-SIZE; COPPER; AL; DISLOCATIONS; TEMPERATURE; MECHANISMS; BEHAVIOR AB Nanocrystalline Al processed by cryogenic ball-milling and nanocrystalline Cu processed by high-pressure torsion at a very low strain rate and at room temperature were investigated using high-resolution transmission electron microscopy. For nanocrystalline Al, we observed partial dislocation emission from grain boundaries, which consequently resulted in deformation stacking faults and twinning. We also observed deformation twins formed via two other mechanisms recently predicted by molecular dynamic simulations. These results are surprising because (1) partial dislocation emission from grain boundaries has not been experimentally observed although it has been predicted by simulations and (2) deformation stacking faults and twinning have not been reported in Al due to its high stacking fault energy. For nanocrystalline Cu, we found that twinning becomes a major deformation mechanism, which contrasts with the literature reports that deformation twinning in coarse-grained Cu occurs only under high strain rate and/or low temperature conditions and that reducing grain sizes suppresses deformation twinning. The investigation of the twinning morphology suggests that twins and stacking faults in nanocrystalline Cu were formed through partial dislocation emissions from grain boundaries. This mechanism differs from the pole mechanism operating in coarse-grained Cu. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Liao, Xiaozhou/B-3168-2009; Zhao, Yonghao/A-8521-2009; Lujan Center, LANL/G-4896-2012; Lavernia, Enrique/I-6472-2013 OI Liao, Xiaozhou/0000-0001-8565-1758; Lavernia, Enrique/0000-0003-2124-8964 NR 28 TC 1 Z9 1 U1 0 U2 9 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 3 EP 10 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300001 ER PT B AU Huang, JY Liao, XZ Zhu, YT Zhou, F Lavernia, EJ AF Huang, JY Liao, XZ Zhu, YT Zhou, F Lavernia, EJ BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Grain boundary structure of nanocrystalline Cu processed by cryomilling SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm DE microstructure; ball milling; HREM; grain boundary ID RESOLUTION ELECTRON-MICROSCOPY; SPECIMEN PREPARATION; DEFORMATION; MICROSTRUCTURE; MECHANISMS; POWDERS; HREM AB The microstructures of cryogenically ball-milled Cu was investigated by high-resolution electron microscopy. It was found that the grain-size reduction is a dislocation-controlled continuous process, consists of the formation of small-angle grain boundaries, a gradual increase of misorientations as a result of accumulation of more dislocations, and finally, the formation of large-angle grain boundaries (GBs). The grain boundaries were generally curved, wavy, and heavily strained, which are typical characteristics of nanostructured materials. In addition, extrinsic dislocations were found in many GBs, indicating that most are in a high-energy, non-equilibrium configuration, which is consistent with observations in equal-channel angular pressing processed Cu, Ni, and Al-Mg, repetitive corrugation and straightening processed Cu and room-temperature ball-milled Cu. These results support a still-disputed concept that GBs in nanostructured metals processed by severe plastic deformation are mostly in non-equilibrium states. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Huang, JY (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Liao, Xiaozhou/B-3168-2009; Huang, Jianyu/C-5183-2008; Lavernia, Enrique/I-6472-2013 OI Liao, Xiaozhou/0000-0001-8565-1758; Lavernia, Enrique/0000-0003-2124-8964 NR 20 TC 0 Z9 0 U1 1 U2 6 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 17 EP 23 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300003 ER PT B AU Beyerlein, IJ Li, S Alexander, DJ Necker, CT Tome, CN Bourke, MA AF Beyerlein, IJ Li, S Alexander, DJ Necker, CT Tome, CN Bourke, MA BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Heterogeneity in texture development in single pass equal channel angular extrusion SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm DE copper; finite element; flow pattern; polycrystalline modeling ID PLASTIC-DEFORMATION; ALUMINUM AB We investigate inhomogeneity in deformation of OFE Cu in a single pass of Equal Channel Angular Extrusion (ECAE). A finite element simulation of the rounded corner die used here shows that deformation occurs primarily over a broad region with an exception of low shear deformation in the round corner region. An analytical model for the deformation history induced by this two-part deformation zone is imported into a viscoplastic self-consistent (VPSC) polycrystalline model for texture prediction. Orientation Image Microscopy (OIM) measurements show that the texture evolution varies from top to the middle by a slight rotation and that the bottom region experiences little deformation but large rotations. Texture predictions agree reasonably well with these OIM measurements in features and intensity. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Beyerlein, IJ (reprint author), Los Alamos Natl Lab, Div Theoret, POB 1663, Los Alamos, NM 87545 USA. RI Li, Saiyi/J-3968-2012 NR 13 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 185 EP 192 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300028 ER PT B AU Alexander, DJ Necker, CT Korzekwa, DA AF Alexander, DJ Necker, CT Korzekwa, DA BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Grain refinement of electron-beam-melted crystal bar zirconium by equal channel angular extrusion SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm ID ZR; EVOLUTION; BEHAVIOR; TEXTURE; ECAP AB Electron-beam (EB) melted crystal bar zirconium has a very low oxygen content (approximately 100 ppm by weight), but a coarse grain structure that needs to be refined to allow successful part fabrication by conventional methods. Cylindrical rods were sectioned from an EB-melted billet by electrodischarge machining, and enclosed in seamless nickel tubing by electron beam welding plugs in each end to make a final billet 9.5 mm in diameter by 50 mm in length. The billet was deformed by equal channel angular extrusion (ECAE) at room temperature in 120degrees tooling. After extrusion for 4 passes via route B. the material was annealed in vacuum for I h at 550degreesC. Because of the low oxygen content, the Zr could be successfully deformed by ECAE to high strains at room temperature. The as-cast grains were extensively subdivided by the processing. A fine uniform grain size of approximately 10 microns was achieved after the anneal, with a weak texture of only 2-3 times random. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Alexander, DJ (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 261 EP 266 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300039 ER PT B AU Alexander, DJ Cooley, JC Thoma, DJ Nobile, A AF Alexander, DJ Cooley, JC Thoma, DJ Nobile, A BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Grain refinement of Arc-melted beryllium-6 wt% copper SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm DE beryllium; grain size; target capsules; texture AB Beryllium doped with 6 weight % copper is the material of choice for fabrication of target capsules for the National Ignition Facility because of its combination of attractive neutronic, physical, and mechanical properties. The target capsules are very small (2 mm in diameter) and thin-walled (150 microns), and the material must be fine-grained and of low inclusion content. Arc-melted Be-Cu. is being produced to eliminate the oxide content. Equal channel angular extrusion (ECAE) is being used to refine the as-cast grain structure. Be-Cu rods have been processed by ECAE at temperatures from 500 to 750degreesC in tooling with a 120degrees angle. Selected samples have been annealed for 1 hour at temperatures from 700 to 775degreesC. The ECAE processing creates a heavily deformed and finely subdivided structure, and the annealing can produce an equiaxed microstructure with a grain size of approximately 20 mum. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Alexander, DJ (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, MST-6, Los Alamos, NM 87545 USA. RI Cooley, Jason/E-4163-2013 NR 4 TC 0 Z9 0 U1 0 U2 2 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 267 EP 272 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300040 ER PT B AU Zhao, YH Liao, XZ Jin, Z Valiev, RZ Zhu, YT AF Zhao, YH Liao, XZ Jin, Z Valiev, RZ Zhu, YT BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Structure and property evolutions of ecaped 7075 Al alloy during annealing SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm DE severe plastic deformation; Al alloy; aging hardening; microhardness; grain size; microstrain; lattice parameter; dislocation density ID MICROSTRUCTURAL EVOLUTION; ALUMINUM-ALLOYS; MAGNESIUM; MG; STABILITY; SYSTEM AB Structure and microhardness evolutions of equal-channel angular pressing (ECAP) processed and coarse-grained (CG) 7075 Al alloys during differential scanning calorimeter (DSC) were investigated by x-ray diffraction (XRD), transmission electron microscopy (TEM) and microhardness measurements. After one-month aging at room temperature, the microhardness of the ECAP processed sample is about 50% larger than that of the CG sample. During DSC annealing, the microhardness of the ECAP processed sample decreased gradually, while a hardening peak appeared for the CG sample. XRD and TEM show that the hardening peak of the CG sample was mainly caused by the precipitation hardening of the Guinier-Preston (GP) zone. For the ECAP processed sample, upon annealing the microstrain (dislocation density) decreased and the crystallites grew, which decreased the hardness and overcompensated the GP zone precipitation hardening. DSC analysis indicates ECAP process only promoted the phase precipitation, but did not change the sequence of phase precipitation. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Zhu, YT (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. RI Liao, Xiaozhou/B-3168-2009; Zhao, Yonghao/A-8521-2009; Lujan Center, LANL/G-4896-2012 OI Liao, Xiaozhou/0000-0001-8565-1758; NR 15 TC 0 Z9 0 U1 0 U2 5 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 511 EP 516 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300080 ER PT B AU Alexander, DJ Beyerlein, IJ AF Alexander, DJ Beyerlein, IJ BE Zhu, YT Langdon, TG Valiev, RZ Semiatin, SL Shin, DH Lowe, TC TI Mechanical properties of high-purity copper processed by equal channel angular extrusion SO ULTRAFINE GRAINED MATERIALS III LA English DT Proceedings Paper CT 3rd International Symposium on Ultrafine Grained Materials CY MAR 15-17, 2004 CL Charlotte, NC SP TMS, mat Proc & MFG Div, Shaping & Forming Comm, TMS, Mech Behav Mat Comm DE equal channel angular extrusion; copper; mechanical properties; anisotropy; texture ID PLASTIC-DEFORMATION; TENSILE DUCTILITY; TITANIUM; TEXTURE; INSTABILITIES; BEHAVIOR; FRACTURE; STRENGTH; METALS; SIZE AB High-purity annealed copper (C10100) has been processed by equal channel angular extrusion for up to 4 passes at room temperature (90degrees tooling, route B-c). Tensile and compression specimens were tested in the as-processed condition to measure the flow properties in 3 orthogonal directions in compression, and in the direction of extrusion for tension. The Cu was initially mechanically isotropic, but developed appreciable anisotropy after the first pass; this anisotropy persisted through all 4 passes. The yield strength in tension was greater than that in compression, in the direction of extrusion. In compression, the yield strength in the side-to-side direction was greater than those in the top-to-bottom or extrusion directions, which were similar. The tensile specimens showed significant total elongation to failure, but most of the elongation was produced by non-uniform deformation. Modeling of the ECAE process with a rigid-plastic viscoplastic self-consistent model showed that the trends observed in the compressive flow properties could be explained by texture development, but could not explain the tension-compression asymmetry. C1 Los Alamos Natl Lab, Mat Sci & Technol Div, Los Alamos, NM 87545 USA. RP Alexander, DJ (reprint author), Los Alamos Natl Lab, Mat Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU MINERALS, METALS & MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086-7514 USA BN 0-87339-571-9 PY 2004 BP 517 EP 522 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA BY82E UT WOS:000189471300081 ER PT S AU Lerche, RA Andrews, DS Bell, PM Griffith, RL AF Lerche, RA Andrews, DS Bell, PM Griffith, RL BE Snyder, DR TI Streak camera performance with large-format CCD readout SO ULTRAHIGH- AND HIGH-SPEED PHOTOGRAPHY, PHOTONICS, AND VIDEOGRAPHY SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Ultrahigh- and High-Speed Photography, Photonics and Videography CY AUG 07-08, 2003 CL San Diego, CA SP SPIE AB The ICF program at Livermore has a large inventory of optical streak cameras that were built in the 1970s and 1980s. The cameras include microchannel plate image-intensifier tubes (IIT) that provide signal amplification and early lens-coupled CCD readouts. Today, these cameras are still very functional, but some replacement parts such as the original streak tube, CCD, and IIT are scarce and obsolete. This article describes recent efforts to improve the performance of these cameras using today's advanced CCD readout technologies. Very sensitive, large-format CCD arrays with efficient fiber-optic input faceplates are now available for direct coupling with the streak tube. Measurements of camera performance characteristics including linearity, spatial and temporal resolution, line-spread function, contrast transfer ratio (CTR), and dynamic range have been made for several different camera configurations: CCD coupled directly to the streak tube, CCD directly coupled to the IIT, and the original configuration with a smaller CCD lens coupled to the IIT output. Spatial resolution (limiting visual) with and without the IIT is 8 and 20 lp/mm, respectively, for photocathode current density up to 25% of the Child-Langmuir (C-L) space-charge limit. Temporal resolution (fwhm) deteriorates by about 20% when the cathode current density reaches 10% of the C-L space charge limit. Streak tube operation with large average tube current was observed by illuminating the entire slit region through a Ronchi ruling and measuring the CTR. Sensitivity (CCD electrons per streak tube photoelectron) for the various configurations ranged from 7.5 to 2,700 with read noise of 7.5 to 10.5 electrons. Optimum spatial resolution is achieved when the IIT is removed. Maximum dynamic range requires a configuration where a single photoelectron from the photocathode produces a signal that is 3 to 5 times the read noise. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lerche, RA (reprint author), Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94551 USA. RI Torres Espallardo, Irene/I-3918-2015 OI Torres Espallardo, Irene/0000-0002-4612-4629 NR 9 TC 1 Z9 1 U1 0 U2 3 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5083-9 J9 P SOC PHOTO-OPT INS PY 2004 VL 5210 BP 1 EP 11 DI 10.1117/12.508397 PG 11 WC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology SC Instruments & Instrumentation; Optics; Imaging Science & Photographic Technology GA BY69Y UT WOS:000189441900001 ER PT J AU Wu, L Schofield, MA Zhu, Y Tafto, J AF Wu, L Schofield, MA Zhu, Y Tafto, J TI A unique determination of boundary condition in quantitative electron diffraction: Application to accurate measurements of mean inner potentials SO ULTRAMICROSCOPY LA English DT Article DE convergent beam electron diffraction; electron holography; mean inner potential; magnesium diboride AB We combine off-axis electron holography and electron shadow imaging to accurately determine the specimen thickness and the incident electron beam direction over the illuminated area of a crystal. We, furthermore, quantify the variations in diffraction intensity with position over the same area. This unique solution to the experimental boundary condition problem enables us to make precise measurements of mean inner electrostatic potentials and structure factors that are sensitive to the bonding characteristics of materials. In this paper, we present the results of mean-inner potential determination from silicon and the newly discovered magnesiumdiboride superconductor. (C) 2003 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Mat Sci, Upton, NY 11973 USA. Univ Oslo, N-0316 Oslo, Norway. RP Zhu, Y (reprint author), Brookhaven Natl Lab, Dept Mat Sci, Bldg 480, Upton, NY 11973 USA. EM zhu@bnl.gov NR 12 TC 5 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JAN PY 2004 VL 98 IS 2-4 BP 135 EP 143 DI 10.1016/j.ultramic.2003.08.006 PG 9 WC Microscopy SC Microscopy GA 812ED UT WOS:000220821900006 PM 15046792 ER PT J AU Liao, XZ Zou, J Cockayne, DJH Matsumura, S AF Liao, XZ Zou, J Cockayne, DJH Matsumura, S TI [001] zone-axis bright-field diffraction contrast from coherent Ge(Si) islands on Si(001) SO ULTRAMICROSCOPY LA English DT Article DE TEM characterization; image simulation; quantum dot ID TRANSMISSION ELECTRON-MICROSCOPY; SEMICONDUCTOR QUANTUM DOTS; VISIBLE LUMINESCENCE; GE ISLANDS; SI(100); SHAPE; RELAXATION; INCLUSION; EVOLUTION; IMAGES AB Coherent Ge(Si)/Si(001) quantum dot islands grown by solid source molecular beam epitaxy at a growth temperature of 700degreesC were investigated using transmission electron microscopy working at 300 kV. The [001] zone-axis bright-field diffraction contrast images of the islands show strong periodicity with the change of the TEM sample substrate thickness and the period is equal to the effective extinction distance of the transmitted beam. Simulated images based on finite element models of the displacement field and using multi-beam dynamical diffraction theory show a high degree of agreement. Studies for a range of electron energies show the power of the technique for investigating composition segregation in quantum dot islands. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Queensland, Ctr Microscopy & Microanalysis, Brisbane, Qld 4072, Australia. Univ Sydney, Australian Key Ctr Microscopy & Microanalysis, Sydney, NSW 2006, Australia. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Univ Queensland, Div Mat, Brisbane, Qld 4072, Australia. Univ Queensland, Ctr Microscopy & Microanalysis, Brisbane, Qld 4072, Australia. Univ Oxford, Dept Mat, Oxford OX1 3PH, England. Kyushu Univ, Dept Appl Quantum Phys & Nucl Engn, Fukuoka 8128581, Japan. RP Zou, J (reprint author), Univ Queensland, Ctr Microscopy & Microanalysis, Brisbane, Qld 4072, Australia. EM j.zou@uq.edu.au RI Liao, Xiaozhou/B-3168-2009; Zou, Jin/B-3183-2009 OI Liao, Xiaozhou/0000-0001-8565-1758; Zou, Jin/0000-0001-9435-8043 NR 26 TC 2 Z9 3 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JAN PY 2004 VL 98 IS 2-4 BP 239 EP 247 DI 10.1016/j.ultramic.2003.08.017 PG 9 WC Microscopy SC Microscopy GA 812ED UT WOS:000220821900018 PM 15046804 ER PT J AU Volkov, VV Zhu, Y AF Volkov, VV Zhu, Y TI Lorentz phase microscopy of magnetic materials SO ULTRAMICROSCOPY LA English DT Article DE exit wave reconstruction; phase retrieval; magnetic imaging; image processing ID TRANSMISSION ELECTRON-MICROSCOPE; OF-INTENSITY EQUATION; FORCE MICROSCOPY; TRANSPORT; REVERSAL; COBALT; SCATTERING; HOLOGRAPHY; RETRIEVAL; OBJECT AB We propose a method of Lorentz phase microscopy for in situ studies and imaging magnetic materials in transmission electron microscopy (TEM) based on the solution of the magnetic transport-of-intensity equation. We also describe the appropriate way of solving this equation that may be useful for understanding and practical use of non-holographic methods for phase retrieval in electron microscopy, especially in imaging magnetic materials. The method is simple, since it is primarily based on classical Fresnel imaging. On the other hand, it is quantitative and can be applied in any TEM without changing the basic hardware. Therefore, it may well find important practical applications in ultramicroscopy and modern magnetic materials research. (C) 2003 Elsevier B.V. All rights reserved. C1 Brookhaven Natl Lab, Mat Sci Dept, Upton, NY 11973 USA. RP Volkov, VV (reprint author), Brookhaven Natl Lab, Mat Sci Dept, Upton, NY 11973 USA. EM volkov@bnl.gov RI Volkov, Vyacheslav/D-9786-2016 NR 32 TC 25 Z9 27 U1 2 U2 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JAN PY 2004 VL 98 IS 2-4 BP 271 EP 281 DI 10.1016/j.ultramic.2003.08.026 PG 11 WC Microscopy SC Microscopy GA 812ED UT WOS:000220821900022 PM 15046808 ER PT S AU Davis, J Berry, N AF Davis, J Berry, N BE Carapezza, EM TI A modular architecture for wireless sensor network nodes SO UNATTENDED/UNMANNED GROUND, OCEAN, AND AIR SENSOR TECHNOLOGIES AND APPLICATIONS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unattended/Unmanned Ground, Ocean and Air Sensor Technologies and Applications VI CY APR 12-15, 2004 CL Orlando, FL SP SPIE DE flexible hardware architecture; task specific computing; sensor networks; event-driven systems AB The system level hardware architecture of individual nodes in a wireless distributed sensor network has not received adequate attention. A large portion of the development work in wireless sensor networks has been devoted to the networking layer or the network communications, but considering the tight integration required between the hardware and software on each node can result in major benefits in power, performance, and usability as well. A novel hardware architecture based on the concept of task specific modular computing provides both the high flexibility and power efficiency required for effective distributed sensing solutions. A comparative power analysis with a traditional, centralized architecture gives a justifying motivation for pursuing the modular architecture.(1) Finally, three decentralized module self-control mechanisms developed to minimize total system power will be presented and explained in detail. C1 Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. RP Davis, J (reprint author), Sandia Natl Labs, Embedded Reasoning Inst, 7011 E Ave, Livermore, CA 94550 USA. NR 21 TC 2 Z9 2 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5340-4 J9 P SOC PHOTO-OPT INS PY 2004 VL 5417 BP 235 EP 249 DI 10.1117/12.542850 PG 15 WC Acoustics; Remote Sensing; Optics; Telecommunications SC Acoustics; Remote Sensing; Optics; Telecommunications GA BAX91 UT WOS:000224145900026 ER PT S AU Davis, J Berry, N AF Davis, J Berry, N BE Carapezza, EM TI Architectural and operational tradeoffs in wireless sensor networks SO UNATTENDED/UNMANNED GROUND, OCEAN, AND AIR SENSOR TECHNOLOGIES AND APPLICATIONS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unattended/Unmanned Ground, Ocean and Air Sensor Technologies and Applications VI CY APR 12-15, 2004 CL Orlando, FL SP SPIE DE metrics; tradeoffs; wireless sensor networks AB Although touted as a revolutionary technology with a wide scope of application, the actual design and implementation of full, end-to-end wireless sensor networks (WSNs) has rarely been demonstrated. One of the primary factors holding back the field is that the capabilities of WSNs and realistic specifications of WSN applications are not well understood. Much research has been devoted to specific hardware, software, or algorithmic components of these networks with very little work having been done on full system implementation for real-world problems. The multitude of WSN components that have been developed result from different tradeoffs made among the parameters governing WSN systems. This paper introduces and analyzes these governing parameters and how tradeoffs are made among them. Utimately, a matching metric presented helps WSN designers use specifications on these parameters to find and integrate appropriate WSN components for implementing real-world WSN solutions. C1 Embedded Reasoning Inst, Sandia Natl Labs, Livermore, CA USA. RP Davis, J (reprint author), Embedded Reasoning Inst, Sandia Natl Labs, 7011 E Ave, Livermore, CA USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5340-4 J9 P SOC PHOTO-OPT INS PY 2004 VL 5417 BP 341 EP 352 DI 10.1117/12.542843 PG 12 WC Acoustics; Remote Sensing; Optics; Telecommunications SC Acoustics; Remote Sensing; Optics; Telecommunications GA BAX91 UT WOS:000224145900037 ER PT S AU Berry, N Davis, J Ko, T Kyker, R Pate, R Stark, D Stinnett, R Baker, J Cushner, A Van Dyke, C Kyckelhahn, B AF Berry, N Davis, J Ko, T Kyker, R Pate, R Stark, D Stinnett, R Baker, J Cushner, A Van Dyke, C Kyckelhahn, B BE Carapezza, EM TI Sense, Decide, Act, Communicate (SDAC): Next generation of smart sensor systems SO UNATTENDED/UNMANNED GROUND, OCEAN, AND AIR SENSOR TECHNOLOGIES AND APPLICATIONS VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Unattended/Unmanned Ground, Ocean and Air Sensor Technologies and Applications VI CY APR 12-15, 2004 CL Orlando, FL SP SPIE DE smart sensor fusion; in-network intelligence; system of systems; disposable sensors AB The recent war on terrorism and increased urban warfare has been a major catalysis for increased interest in the development of disposable unattended wireless ground sensors. While the application of these sensors to hostile domains has been generally governed by specific tasks, this research explores a unique paradigm capitalizing on the fundamental functionality related to sensor systems. This functionality includes a sensors ability to (S) under bar ense-multi-modal sensing of environmental events, (D) under bar ecide-smart analysis of sensor data, (A) under bar ct-response to environmental events, and (C) under bar ommunication-internal to system and external to humans (SDAC). The main concept behind SDAC sensor systems is to integrate the hardware, software, and networking to generate 'knowledge and not just data'. This research explores the usage of wireless SDAC units to collectively make up a sensor system capable of persistent, adaptive, and autonomous behavior. These systems are base on the evaluation of scenarios and existing systems covering various domains. This paper presents a promising view of sensor network characteristics, which will eventually yield smart (intelligent collectives) network arrays of SDAC sensing units generally applicable to multiple related domains. This paper will also discuss and evaluate the demonstration system developed to test the concepts related to SDAC systems. C1 Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. RP Berry, N (reprint author), Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. NR 4 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5340-4 J9 P SOC PHOTO-OPT INS PY 2004 VL 5417 BP 370 EP 381 DI 10.1117/12.542893 PG 12 WC Acoustics; Remote Sensing; Optics; Telecommunications SC Acoustics; Remote Sensing; Optics; Telecommunications GA BAX91 UT WOS:000224145900040 ER PT B AU Bode, BM Hill, JJ Benjegerdes, TR AF Bode, BM Hill, JJ Benjegerdes, TR GP USENIX Assoc TI Cluster interconnect overview SO USENIX ASSOCIATION PROCEEDINGS OF THE FREENIX TRACK 2004 USENIX ANNUAL TECHNICAL CONFERENCE LA English DT Proceedings Paper CT 2004 USENIX Annual Technology Conference CY JUN 27-JUL 02, 2004 CL Boston, MA SP USENIX Assoc AB Today cluster computers are more commonplace than ever and there are a variety of choices for the interconnect. The right choice for a particular installation will depend on a variety of factors including price, raw performance, scalability, etc. This paper will present an over-view of the popular network technologies available today including Gigabit Ethernet, 10 Gigabit Ethernet, Myrinet, SCI, Quadrics, and InfiniBand. Where possible a comparison will be included for multiple vendors of a given technology. Included will be comparisons of cost and performance of each along with suggestions for when each might present the best choice for a cluster installation. C1 Ames Lab, Scalable Comp Lab, Ames, IA 50011 USA. RP Bode, BM (reprint author), Ames Lab, Scalable Comp Lab, Ames, IA 50011 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU USENIX ASSOC PI BERKELEY PA SUITE 215, 2560 NINTH ST, BERKELEY, CA 94710 USA BN 1-931971-22-6 PY 2004 BP 211 EP 217 PG 7 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA BAW79 UT WOS:000223966400022 ER PT B AU Sorescu, DC Boatz, JA Thompson, DL AF Sorescu, DC Boatz, JA Thompson, DL GP ieee computer society TI First principles calculations of the chemisorption properties of nitro-containing molecules on the Al2O3(0001) surface SO USERS GROUP CONFERENCE, PROCEEDINGS LA English DT Proceedings Paper CT Users Group Conference CY JUN 07-11, 2004 CL Williamsburg, VA SP User Advocacy Grp, HPCMPO Outreach Team ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; METALS AB First-principles calculations based on density functional theory (DFT) and the generalized gradient approximation (GGA) have been used to study the adsorption of nitromethane (NM and 1,1-diamino-2,2-dinitroethylene (FOX7) molecules on the basal plane of alpha-Al2O3 crystal. The calculations employ a (2x2) supercell slab model and 3D periodic boundary conditions. Based on these calculations we have determined that both NM and FOX7 molecules can adsorb nondissociatively on the surface, with the most stable adsorption configurations parallel to the surface. The corresponding binding energies are found in the range 25.3-26.0 kcal/mol for NM and 35.6-48.3 kcal/mol for FOX-7 depending on the relative molecular orientation and the corresponding surface sites. The minimum energy pathways for NM dissociation have been determined and a low energy pathway leading to H elimination with formation of adsorbed CH2NO2, and hydroxyl species has been identified. Additional calculations have focused on adsorption properties of aci-nitromethane tautomers and on description of the energetic pathways connecting adsorbed nitromethane molecule with these tautomers. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Sorescu, DC (reprint author), US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. NR 13 TC 1 Z9 1 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-7695-2259-9 PY 2004 BP 2 EP 6 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering; Engineering, Electrical & Electronic; Mechanics SC Computer Science; Engineering; Mechanics GA BBP31 UT WOS:000226863200001 ER PT S AU Tajima, H Madejski, G Mitani, T Tanaka, T Nakamura, H Nakazawa, K Takahashi, T Fukazawa, Y Kamae, T Kokubun, M Marlow, D Nomachi, M Silva, EDE AF Tajima, H Madejski, G Mitani, T Tanaka, T Nakamura, H Nakazawa, K Takahashi, T Fukazawa, Y Kamae, T Kokubun, M Marlow, D Nomachi, M Silva, EDE BE Hasinger, G Turner, MJL TI Gamma-ray polarimetry with Compton telescope SO UV AND GAMMA-RAY SPACE TELESCOPE SYSTEMS, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on UV and Gamma-Ray Space Telescope Systems CY JUN 21-24, 2004 CL Glasgow, SCOTLAND SP SPIE DE gamma-ray; Compton telescope; polarimeter; silicon strip detector; CdTe; semiconductor detector ID MULTIWAVELENGTH OBSERVATIONS; DETECTOR; ENERGY AB Compton telescope is a promising technology to achieve very high sensitivity in the soft gamma-ray band (0.1-10 MeV) by utilizing Compton kinematics. Compton kinematics also enables polarization measurement which will open new windows to study gamma-ray production mechanism in the universe. CdTe and Si semiconductor technologies are key technologies to realize the Compton telescope in which their high energy resolution is crucial for high angular resolution and back-round rejection capability. We have assembled a prototype module using a double-sided silicon strip detector and CdTe pixel detectors. In this paper, we present expected polarization performance of a proposed mission (NeXT/SGD). We also report results from polarization measurements using polarized synchrotron light and validation of EGS4 MC simulation. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Tajima, H (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 24 TC 11 Z9 12 U1 1 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5420-6 J9 P SOC PHOTO-OPT INS PY 2004 VL 5488 BP 561 EP 571 DI 10.1117/142.552487 PN 1-2 PG 11 WC Engineering, Aerospace; Instruments & Instrumentation; Optics SC Engineering; Instruments & Instrumentation; Optics GA BBD21 UT WOS:000224987100055 ER PT B AU Austin, BA Guzik, JA Despain, KM Templeton, MR AF Austin, BA Guzik, JA Despain, KM Templeton, MR BE Kurtz, DW Pollard, KR TI Nonlinear radial pulsations for hot 20-M-circle dot models SO VARIABLE STARS IN THE LOCAL GROUP SE Astronomical Society of the Pacific Conference Series LA English DT Proceedings Paper CT IAU Colloquium 193 on Variable Stars in the Local Group CY JUL 06-11, 2003 CL Univ Canterbury, Christchurch, NEW ZEALAND SP Int Astronom Union HO Univ Canterbury ID STELLAR EVOLUTION; MAIN SEQUENCE; OPAL; STAR AB We present the results of calculations that predict a radial pulsation instability region for hot 20-Mcircle dot stars within a narrow band around T-eff = 22, 000 K. These models have exhausted core hydrogen and are undergoing shell hydrogen burning, and have luminosities similar to the most massive beta Cephei stars, but are slightly cooler and more evolved. The pulsations grow to a radial velocity amplitude of similar to20 km s(-1) with a period of similar to0.75 d. The amplitude increases for higher Z and lower Y models. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Austin, BA (reprint author), Los Alamos Natl Lab, X-2,MS T085, Los Alamos, NM 87545 USA. EM ben_austin_nz@yahoo.com; joy@lanl.gov NR 12 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-162-1 J9 ASTR SOC P PY 2004 VL 310 BP 453 EP 457 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAE85 UT WOS:000221910700086 ER PT B AU Guzik, JA Austin, BA Bradley, PA Cox, AN AF Guzik, JA Austin, BA Bradley, PA Cox, AN BE Kurtz, DW Pollard, KR TI Does extreme mixing improve frequency agreement for delta Scuti stars? SO VARIABLE STARS IN THE LOCAL GROUP SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium 193 on Variable Stars in the Local Group CY JUL 06-11, 2003 CL Univ Canterbury, Christchurch, NEW ZEALAND SP Int Astronom Union HO Univ Canterbury ID FG-VIRGINIS; ASTEROSEISMOLOGY AB delta Scuti stars that have been observed intensely by the Delta Scuti Network and other campaigns exhibit fewer modes than predicted in the observed frequency range. In addition, some modes are difficult to match by the most likely observable l = 0, 1, and 2 modes, especially considering available spectroscopic mode identifications. Here we examine frequency predictions for stellar models for FG Vir and 4 CVn with extensive core mixing, well beyond the plausible limits of such mixing from convective core overshooting. We find that mixing has the potential to substantially improve frequency agreement, and deserves further investigation. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Guzik, JA (reprint author), Los Alamos Natl Lab, X-2,MS T085, Los Alamos, NM 87545 USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-162-1 J9 ASTR SOC P PY 2004 VL 310 BP 462 EP 465 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAE85 UT WOS:000221910700088 ER PT B AU Bradley, PA AF Bradley, PA BE Kurtz, DW Pollard, KR TI Analysis of long-term single-site observations of the pulsating DB white dwarf GD 358 SO VARIABLE STARS IN THE LOCAL GROUP SE ASTRONOMICAL SOCIETY OF THE PACIFIC CONFERENCE SERIES LA English DT Proceedings Paper CT IAU Colloquium 193 on Variable Stars in the Local Group CY JUL 06-11, 2003 CL Univ Canterbury, Christchurch, NEW ZEALAND SP Int Astronom Union HO Univ Canterbury ID WHOLE EARTH TELESCOPE; FREQUENCIES; SPECTRA AB We briefly describe the analysis of single-site data collected from 1982 to 1992 for the pulsating DB white dwarf GD 358. We show that the amplitudes of almost all of the l = 1. modes change over time, and some of the l = I modes disappear for months at a time. We also find a new mode at k = 19, with a frequency of similar to1173 muHz. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bradley, PA (reprint author), Los Alamos Natl Lab, X-2 MS B220, Los Alamos, NM 87545 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ASTRONOMICAL SOC PACIFIC PI SAN FRANCISCO PA 390 ASHTON AVE, SAN FRANCISCO, CA 94112 USA BN 1-58381-162-1 J9 ASTR SOC P PY 2004 VL 310 BP 506 EP 510 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BAE85 UT WOS:000221910700097 ER PT S AU Weeratunga, SK Kamath, C AF Weeratunga, SK Kamath, C BE Panchanathan, S Vasudev, B TI An investigation of implicit active contours for scientific image segmentation SO VISUAL COMMUNICATIONS AND IMAGE PROCESSING 2004, PTS 1 AND 2 SE Proceedings of SPIE LA English DT Proceedings Paper CT Conference on Visual Communications and Image Processing 2004 CY JAN 20-22, 2004 CL San Jose, CA SP Soc Imaging Sci & Technol, SPIE DE level set; implicit active contour; image segmentation; edge detection AB The use of partial differential equations in image processing has become an active area of research in the last few years. In particular, active contours are being used for image segmentation, either explicitly as snakes, or implicitly through the level set approach. In this paper, we consider the use of the implicit active contour approach for segmenting scientific images of pollen grains obtained using a scanning electron microscope. Our goal is to better understand the pros and cons of these techniques and to compare them with the traditional approaches such as the Canny and SUSAN edge detectors. The preliminary results of our study show that the level set method is computationally expensive and requires the setting of several different parameters. However, it results in closed contours, which may be useful in separating objects from the background in an image. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94551 USA. EM kamath2@llnl.gov NR 23 TC 9 Z9 9 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5211-4 J9 PROC SPIE PY 2004 VL 5308 BP 210 EP 221 DI 10.1117/12.527037 PN 1&2 PG 12 WC Computer Science, Information Systems; Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BY80X UT WOS:000189468200022 ER PT S AU Cheung, SCS Kamath, C AF Cheung, SCS Kamath, C BE Panchanathan, S Vasudev, B TI Robust techniques for background subtraction in urban traffic video SO VISUAL COMMUNICATIONS AND IMAGE PROCESSING 2004, PTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Communications and Image Processing 2004 CY JAN 20-22, 2004 CL San Jose, CA SP Soc Imaging Sci & Technol, SPIE DE background subtraction; urban traffic video ID REAL-TIME TRACKING; SHADOWS AB Identifying moving objects from a video sequence is a fundamental and critical task in many computer-vision applications. A common approach is to perform background subtraction, which identifies moving objects from the portion of a video frame that differs significantly from a background model. There are many challenges in developing a good background subtraction algorithm. First, it must be robust against changes in illumination. Second, it should avoid detecting non-stationary background objects such as swinging leaves, rain, snow, and shadow cast by moving objects. Finally., its internal background model should react quickly to changes in back-round such as startino, and stopping of vehicles. In this paper we compare various background subtraction algorithms for detecting moving vehicles and pedestrians in urban traffic video sequences. We consider approaches varying from simple techniques such as frame differencing and adaptive median filtering. to more sophisticated probabilistic modeling techniques. While complicated techniques often produce superior performance, our experiments show that simple techniques such as adaptive median filtering can produce good results with much lower computational complexity. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. RP Cheung, SCS (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, 7000 East Ave, Livermore, CA 94550 USA. NR 34 TC 147 Z9 150 U1 0 U2 13 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5211-4 J9 P SOC PHOTO-OPT INS PY 2004 VL 5308 BP 881 EP 892 DI 10.1117/12.526886 PN 1&2 PG 12 WC Computer Science, Information Systems; Computer Science, Software Engineering; Imaging Science & Photographic Technology SC Computer Science; Imaging Science & Photographic Technology GA BY80X UT WOS:000189468200087 ER PT S AU Ko, T Berry, N Kyker, R AF Ko, T Berry, N Kyker, R BE Rahman, ZU Schowengerdt, RA Reichenbach, SE TI A minimalistic approach to image processing for low-power sensor networks SO VISUAL INFORMATION PROCESSING XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing XIII CY APR 15-16, 2004 CL Orlando, FL SP SPIE AB Wireless sensor networks allow detailed sensing of otherwise unknown and inaccessible environments. While it would be beneficial to include cameras in a wireless sensor network because images are so rich in information, the power cost of transmitting an image across the wireless network can dramatically shorten the lifespan of the sensors. This paper investigates various compression techniques and what the cost of these algorithms would be to the lifespan of the sensor nodes. We further describe a new paradigm for cameras and wireless networks. Rather than focusing on transmitting images across the network, we show how an image can be processed locally for key features using simple detectors. Contrasted with traditional event detection systems that trigger a an image capture, this enables a new class of sensors which uses a low power imaging sensor to detect a variety of visual cues. C1 Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. RP Ko, T (reprint author), Sandia Natl Labs, Embedded Reasoning Inst, Livermore, CA 94550 USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5361-7 J9 P SOC PHOTO-OPT INS PY 2004 VL 5438 BP 51 EP 62 DI 10.1117/12.542592 PG 12 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BAS06 UT WOS:000223341800006 ER PT S AU Love, RJ Horsthemke, W Macal, C Van Groningen, C AF Love, RJ Horsthemke, W Macal, C Van Groningen, C BE Rahman, ZU Schowengerdt, RA Reichenbach, SE TI Spatio-temporal animation of Army logistics simulations, facilitating analysis of military deployments SO VISUAL INFORMATION PROCESSING XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Visual Information Processing XIII CY APR 15-16, 2004 CL Orlando, FL SP SPIE DE animation; visualization; analysis; military; deployment; spatio-temporal; spatial; discrete event; simulation AB Visualization techniques for simulations are often limited to statistical reports, graphs, and charts, but simulations can be enhanced through the use of animation. A spatio-temporal animation allows a viewer to observe a simulation operate, rather than deduce it from numerical output. The Route Viewer, developed by Argonne National Laboratory, is a two-dimensional animation model that animates the objects and events produced by a discrete event simulation. It operates in a playback mode, whereby a simulated scenario is animated after the simulation has completed. The Route Viewer is used to verify the simulation's processes and data, but it also benefits the simulation as an analytical tool by facilitating spatial and temporal analysis. By visualizing the events of a simulated scenario in two-dimensional space, it is possible to determine whether the scenario, or simulation model, is reasonable. Further, the Route Viewer provides an awareness of what happens in a scenario, when it happens, and the completeness and efficiency of the scenario and its processes. For Army deployments, it highlights utilization of resources and where bottlenecks are occurring. This paper discusses how the Route Viewer facilitates the analysis of military deployment simulation model results. C1 Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA. RP Love, RJ (reprint author), Argonne Natl Lab, Decis & Informat Sci Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5361-7 J9 P SOC PHOTO-OPT INS PY 2004 VL 5438 BP 282 EP 289 DI 10.1117/12.542583 PG 8 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA BAS06 UT WOS:000223341800030 ER PT S AU Curlee, TR Busch, IK Hilliard, MR Oladosu, G Southworth, F Vogt, DP AF Curlee, TR Busch, IK Hilliard, MR Oladosu, G Southworth, F Vogt, DP GP TRB TI Economic foundations of Ohio River Navigation Investment Model SO WATER TRANSPORT SE TRANSPORTATION RESEARCH RECORD LA English DT Article; Proceedings Paper CT 83rd Annual Meeting of the Transportation-Research-Board CY JAN 11-15, 2004 CL Washington, DC SP Transportat Res Board, US Dept Transportat, US Bur Transportat Stat, US Fed Aviat Adm, US Fed Highway Adm, US Fed Motor Carrier Safety Adm, US Fed Railroad Adm, US FedTransit Adm, US Natl Highway Traff Safety Adm, US Res& Special Programs Adm, NASA, USA Corps Engineers, US Coast Guard, US DOE, US EPA ID FREIGHT TRANSPORTATION; DEMAND C1 Oak Ridge Natl Lab, Ctr Transportat Anal, Natl Transportat Res Ctr, Knoxville, TN 37932 USA. RP Curlee, TR (reprint author), Oak Ridge Natl Lab, Ctr Transportat Anal, Natl Transportat Res Ctr, 2360 Cherahala Blvd, Knoxville, TN 37932 USA. RI Hilliard, Michael/C-3270-2016 OI Hilliard, Michael/0000-0002-4450-9250 NR 18 TC 0 Z9 0 U1 1 U2 3 PU TRANSPORTATION RESEARCH BOARD NATL RESEARCH COUNCIL PI WASHINGTON PA 500 FIFTH ST, NW, WASHINGTON, DC 20001 USA SN 0361-1981 BN 0-309-09465-8 J9 TRANSPORT RES REC PY 2004 IS 1871 BP 13 EP 23 PG 11 WC Engineering, Civil; Transportation; Transportation Science & Technology SC Engineering; Transportation GA BBQ91 UT WOS:000227333300003 ER PT S AU Langdon, VL Hilliard, MR Busch, IK AF Langdon, VL Hilliard, MR Busch, IK GP TRB TI Future utilization and optimal investment strategy for inland waterways - New model from US Army Corps of Engineers to assist policy makers SO WATER TRANSPORT SE TRANSPORTATION RESEARCH RECORD LA English DT Article; Proceedings Paper CT 83rd Annual Meeting of the Transportation-Research-Board CY JAN 11-15, 2004 CL Washington, DC SP Transportat Res Board, US Dept Transportat, US Bur Transportat Stat, US Fed Aviat Adm, US Fed Highway Adm, US Fed Motor Carrier Safety Adm, US Fed Railroad Adm, US FedTransit Adm, US Natl Highway Traff Safety Adm, US Res& Special Programs Adm, NASA, USA Corps Engineers, US Coast Guard, US DOE, US EPA AB For nearly three decades, the U.S. Army Corps of Engineers (the Corps) has been measuring incremental system navigation transportation costs for proposed infrastructure investments in search of the National Economic Development (NED) plan: local optimization in a system-level evaluation. The increasingly complex and sophisticated analysis requires the development of additional modeling modules. The traditional analysis assumed a most-likely traffic forecast and a set investment timing. Cost-benefit analyses on various alternatives were compared to determine the without-project condition and the recommended with-project NED plan. Sensitivity analyses of traffic forecasts and investment timing were done on the with-project plan. The second generation of analysis factored in the impacts of scheduled chamber closure differences between alternatives, and the third generation of analysis factored in the impacts of unscheduled ones. The goal is to be able to optimize investments simultaneously across a system (not just investments at one site) under a series of forecast scenarios while capturing structural reliability differences (scheduled and unscheduled closures). As the demands of the analysis increased, there was a need to consolidate and dynamically link the various models and techniques developed over the years and to develop new techniques to simultaneously manage investment permutations and automatically select optimal investment plans; the desire was to perform system optimization in a system-level evaluation. The innovative analysis techniques and relational database management structure of the new Ohio River Navigation Investment Model are introduced, as is a set of flexible, integrated analysis modules that move the Corps closer to these ideals. C1 USA, Corps Engn, Navigat Planning Ctr, Huntington, WV 25701 USA. Oak Ridge Natl Lab, Ctr Transportat Anal, Natl Transportat Res Ctr, Knoxville, TN 37932 USA. RP Langdon, VL (reprint author), USA, Corps Engn, Navigat Planning Ctr, 502 8th St, Huntington, WV 25701 USA. RI Hilliard, Michael/C-3270-2016 OI Hilliard, Michael/0000-0002-4450-9250 NR 3 TC 0 Z9 0 U1 1 U2 3 PU TRANSPORTATION RESEARCH BOARD NATL RESEARCH COUNCIL PI WASHINGTON PA 500 FIFTH ST, NW, WASHINGTON, DC 20001 USA SN 0361-1981 BN 0-309-09465-8 J9 TRANSPORT RES REC PY 2004 IS 1871 BP 33 EP 41 PG 9 WC Engineering, Civil; Transportation; Transportation Science & Technology SC Engineering; Transportation GA BBQ91 UT WOS:000227333300005 ER PT S AU Straub, TM Quinonez-Diaz, MD Valdez, CO Call, DR Chandler, DP AF Straub, TM Quinonez-Diaz, MD Valdez, CO Call, DR Chandler, DP BE Marshall, M TI Using DNA microarrays to detect multiple pathogen threats in water SO WATERBORNE PATHOGENS SE WATER SCIENCE AND TECHNOLOGY: WATER SUPPLY LA English DT Proceedings Paper CT International Symposium on Waterborne Pathogens CY 2002 CL Lisbon, PORTUGAL SP Amer Water Work Assoc, Int Water Assoc, EPAL, Lab Nacl Engenharia Civil, Amer Water Works Assoc Res Fdn DE DNA microarrays; multiplexed pathogen detection; single nucleotide polymorphisms ID CRYPTOSPORIDIUM OOCYSTS; HELICOBACTER-PYLORI; GENE; PCR; HYBRIDIZATION AB We present four studies that illustrate the use of DNA microarrays for the detection and subsequent genotyping of waterborne pathogens. A genotyping array targeting four virulence factor genes in enterohemorrhagic Escherichia coli (EHEC) was tested. The arrays were clearly able to differentiate between E coli O157:H7 genotypes and E coli O91:H2. Non-pathogenic E coli and non-target organisms were not detected on this array. In the second study, an hsp70 gene single nucleotide polymorphism (SNP) array for specific Cryptosporidium parvum detection was constructed to differentiate between principle genotypes. SNPs, and hence differences between genotypes, were easily detected on this type of array. In the third study an array for Helicobacter pylori was tested for simultaneous SNP discrimination and presence or absence of virulence factor genes. Results from this study showed that both SNP discrimination for some conserved genes, and the presence or absence of virulence factor genes was possible. In the fourth study, multiplexing was achieved by direct hybridization and detection of mRNA to the array. For highly expressed genes, visible signal was detected at 312.5 ng of total RNA, indicating that these new methods may have sufficient environmental sensitivity without the need to perform PCR. C1 Pacific NW Natl Lab, Environm Microbiol Grp, Richland, WA 99352 USA. Washington State Univ, Dept Vet Microbiol & Pathol, Pullman, WA 99164 USA. Argonne Natl Lab, Biochip Technol Grp, Argonne, IL 60439 USA. RP Straub, TM (reprint author), Pacific NW Natl Lab, Environm Microbiol Grp, 902 Battelle Blvd,MS P7-50, Richland, WA 99352 USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU I W A PUBLISHING PI LONDON PA ALLIANCE HOUSE, 12 CAXTON ST, LONDON SW1H 0QS, ENGLAND SN 1606-9749 BN 1-84339-465-0 J9 WA SCI TECHNOL PY 2004 VL 4 IS 2 BP 107 EP 114 PG 8 WC Microbiology; Water Resources SC Microbiology; Water Resources GA BAH92 UT WOS:000222330300016 ER PT J AU Hershberger, J Ajayi, OO Zhang, J Yoon, H Fenske, GR AF Hershberger, J Ajayi, OO Zhang, J Yoon, H Fenske, GR TI Formation of austenite during scuffing failure of SAE 4340 steel SO WEAR LA English DT Article DE scuffing; diffraction; austenite; phase transformation ID WHITE-ETCHING LAYERS; RUNNING-IN; PART-I; X-RAY; CONTACTS; SURFACE; TRANSFORMATIONS; TEMPERATURE; LUBRICATION; MECHANISMS AB Scuffing failure was induced in samples of SAE 4340 steel which had been quenched and annealed at several temperatures. Examination of worn areas using grazing-incidence X-ray diffraction revealed an austenitic phase at volume fractions of up to 60%. No dependence of austenite fraction on depth was observed for depths of up to 5.0 mum. No clear trend in austenite fraction after scuffing as a function of tempering temperature was found. One wear test was interrupted precisely during scuffing, and the worn areas of that sample showed 15% austenite. A fully scuffed sample of the same tempering temperature contained 60% austenite, while analysis of original material and contact areas prior to scuffing initiation revealed no austenite. Observations from the present work suggest that austenite formation was caused by scuffing and not the other way around. Austenite may have formed due to a rapid austenitization process, mechanical dissolution of carbides, or a diffusionless transformation. Once formed, the austenite may have been stabilized by stress or by small crystallite size, but not likely by compositional change. Use of the Advanced Photon Source at Argonne National Laboratory was supported by the US Department of Energy under Contract W-31-109-ENG-38. (C) 2003 Elsevier B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Caterpillar Inc, Argonne, IL 60439 USA. RP Hershberger, J (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave,Bldg 2-12,Room D204, Argonne, IL 60439 USA. EM jhersh@anl.gov NR 27 TC 14 Z9 14 U1 1 U2 9 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD JAN PY 2004 VL 256 IS 1-2 BP 159 EP 167 DI 10.1016/S0043-1648(03)00375-2 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 762EP UT WOS:000187958700022 ER PT J AU Dave, VR Cola, MJ Kumar, M Schwartz, AJ Hussen, GNA AF Dave, VR Cola, MJ Kumar, M Schwartz, AJ Hussen, GNA TI Grain boundary character in Alloy 690 and ductility-dip cracking susceptibility SO WELDING JOURNAL LA English DT Article DE weldability; Alloy 690; ductility-dip cracking; grain boundary character; distribution; special grain boundaries; hot ductility testing ID POLYCRYSTALS; TOUGHNESS; CREEP AB A complete elucidation of the physical mechanisms responsible for intermediate temperature ductility loss in metals (ductility dip) is elusive. This article provides insight pertaining to ductility-dip cracking in Alloy 690, namely that the fraction and interconnectivity of low-energy coincidence site lattice grain boundaries have a pronounced effect on material susceptibility to ductility-dip cracking. In this work, as-received wrought Alloy 690 is compared to Alloy 690 that was strain annealed to achieve a different configuration of special boundaries. Hot ductility tests are performed using a Gleeble(TM) thermomechanical simulator. It is shown that the intermediate temperature ductility dip is less pronounced in the strain-annealed material, that it is shifted toward lower temperatures, and that the on-cooling ductility recovery temperature (DRT) is higher. Scanning electron microscope fracto-graphic analysis is coupled with electron backscattered diffraction (EBSD) pattern analysis to provide a preliminary metallurgical explanation of this improvement. It is qualitatively shown that improving the topological connectivity of these special boundaries in Alloy 690 enhances material resistance to cracking. Although this current study does not examine all possible factors contributing to ductility-dip cracking (DDC), it does suggest that grain boundary character and specifically the topological connectivity of special boundaries are important but, previously, not widely appreciated microstructural influencing factors in DDC. C1 Los Alamos Natl Lab, Nucl Mat & Technol Div, Los Alamos, NM 87544 USA. Lawrence Livermore Natl Lab, Chem & Mat Directorate, Livermore, CA USA. Stanford Univ, Dept Mat Sci & Engn, Palo Alto, CA 94304 USA. RP Dave, VR (reprint author), Los Alamos Natl Lab, Nucl Mat & Technol Div, Los Alamos, NM 87544 USA. NR 21 TC 29 Z9 30 U1 0 U2 4 PU AMER WELDING SOC PI MIAMI PA 550 N W LEJEUNE RD, MIAMI, FL 33126 USA SN 0043-2296 J9 WELD J JI Weld. J. PD JAN PY 2004 VL 83 IS 1 BP 1S EP 5S PG 5 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA 759TV UT WOS:000187753700008 ER PT S AU Gunderson, K Chen, CMH Christensen, F Craig, W Decker, T Hailey, C Harrison, F McLean, R Wurtz, R Ziock, K AF Gunderson, K Chen, CMH Christensen, F Craig, W Decker, T Hailey, C Harrison, F McLean, R Wurtz, R Ziock, K BE Flanagan, KA Siegmund, OHW TI Ground performance of the High-Energy Focusing Telescope (HEFT) attitude control system SO X-RAY AND GAMMA-RAY INSTRUMENTATION FOR ASTRONOMY XIII SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray and Gamma-Ray Instrumentation for Astronomy XIII CY AUG 03-05, 2003 CL San Diego, CA SP SPIE DE balloons; attitude control systems; X-rays AB The High Energy Focusing Telescope (HEFT) is a balloon-borne, hard x-ray/gamma ray (20-70 keV) astronomical experiment. HEFT's 10 arcminute field of view and 1 arcminute angular resolution place challenging demands on its attitude control system (ACS). A microprocessor-based ACS has been developed to manage target acquisition and sidereal tracking. The ACS consists of a variety of sensors and actuators, with provisions for 2-way ground communication, all controlled by an on-board computer. Ground based pointing performance measurements indicate la jitter of 7" and gyro drift rates of < 1" s(-1). Jitter is expected to worsen in the flight environment, but star tracker data are expected to reduce drift rates significantly, enabling a predicted la absolute attitude determination of greater than or equal to4.7". HEFT is scheduled for flight in Spring 2004. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gunderson, K (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5038-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5165 BP 158 EP 168 DI 10.1117/12.513439 PG 11 WC Engineering, Aerospace; Astronomy & Astrophysics; Instruments & Instrumentation; Optics SC Engineering; Astronomy & Astrophysics; Instruments & Instrumentation; Optics GA BY69W UT WOS:000189441700018 ER PT S AU Kang, HC Stephenson, GB Liu, C Conley, R Macrander, AT Maser, J Bajt, S Chapman, HN AF Kang, HC Stephenson, GB Liu, C Conley, R Macrander, AT Maser, J Bajt, S Chapman, HN BE MacDonald, CA Macrander, AT Ishikawa, T Morawe, C Wood, JL TI Synchrotron x-ray study of multilayers in Laue geometry SO X-RAY SOURCES AND OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray Sources and Optics CY AUG 02-03, 2004 CL Denver, CO SP SPIE DE x-ray optics; multilayer; Laue diffraction; focusing ID FRESNEL ZONE-PLATE; DIFFRACTION AB Zone plates with depth to zone-width ratios as large as 100 are needed for focusing of hard x-rays. Such high aspect ratios are challenging to produce by lithography. We are investigating the fabrication of high-aspect-ratio linear zone plates by multilayer deposition followed by sectioning. As an initial step in this work, we present a synchrotron x-ray study of constant-period multilayers diffracting in Laue (transmission) geometry. Data are presented from two samples: a 200 period W/Si multilayer with d-spacing of 29 nm, and a 2020 period Mo/Si multilayer with d-spacing of 7 nm. By cutting and polishing we have successfully produced thin cross sections with section depths ranging from 2 to 12 mum. Transverse scattering profiles (rocking curves) across the Bragg reflection exhibit well-defined interference fringes originating from the depth of the sample, in agreement with dynamical diffraction theory for a multilayer in Laue geometry. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Stephenson, GB (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Conley, Ray/C-2622-2013; Maser, Jorg/K-6817-2013 NR 17 TC 6 Z9 6 U1 0 U2 2 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5475-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5537 BP 127 EP 132 DI 10.1117/12.560173 PG 6 WC Optics SC Optics GA BBJ12 UT WOS:000225736100014 ER PT S AU Liu, CA Conley, R Macrander, AT Graber, T Morawe, C Borel, C Dufresne, EM AF Liu, CA Conley, R Macrander, AT Graber, T Morawe, C Borel, C Dufresne, EM BE MacDonald, CA Macrander, AT Ishikawa, T Morawe, C Wood, JL TI Small d-spacing WSi2/Si narrow bandpass multilayers SO X-RAY SOURCES AND OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray Sources and Optics CY AUG 02-03, 2004 CL Denver, CO SP SPIE DE x-ray optics; multilayer mirrors; sputter deposition AB To develop narrow-bandpass multilayer monochromators, we have studied small d-spacing WSi2/Si multilayers. We found that WSi2/Si is an excellent multilayer system for achieving both the desired spectral resolution and peak reflectivity. Compared to other traditional multilayer systems such as W/Si, WSi2/Si not only has a lower density and lower absorption, but also is a chemically more stable system, since WSi2 is already a silicide. One thus expects better thermal stability and sharper interfaces for WSi2/Si multilayers. There are two approaches to achieve high-resolution multilayers: either decrease the d spacing or use low absorption materials. By using WSi2/Si. we can utilize both approaches in the same system to achieve good energy resolution and peak reflectivity. Another advantage of this system is that the sputtering rate for Si is much higher than other traditional low-Z materials. Several WSi2/Si multilayers have been fabricated at the Advanced Photon Source (APS) deposition lab using dc magnetron sputtering with constant currents of 0.5 A in Ar at a pressure of 2.3 mTorr. A test sample of [9.65Angstrom-WSi2/10.05Angstrom-Si] X 300 was studied at four institutions: using laboratory x-ray diffractometers with Cu Kalpha (8.048 keV) wavelength at the APS x-ray lab and at European Synchrotron Radiation Facility (ESRF). and using synchrotron undulator x-rays at 10 keV at MHATT-CAT and at 25 keV at ChemMatCARS-CAT of the APS. The measured first-order reflectivity was 54% with a bandpass of 0.46% at 10 keV and 66% reflectivity with a bandpass of 0.67% at 25 keV of undulator x-rays. Similar results were obtained from Cu Kalpha x-rays. This result is very attractive for the design of a multilayer monochromator for the ChemMatCARS-CAT to be used in the 20 to 25 keV range. Other small d-spacing multilayers are being studied. Comparison between WSi2/Si and W/Si multilayers will be discussed. C1 Argonne Natl Lab, Expt Facil Div, Argonne, IL 60439 USA. RP Liu, CA (reprint author), Argonne Natl Lab, Expt Facil Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Conley, Ray/C-2622-2013 NR 13 TC 11 Z9 11 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5475-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5537 BP 154 EP 160 DI 10.1117/12.561399 PG 7 WC Optics SC Optics GA BBJ12 UT WOS:000225736100017 ER PT S AU Khachatryan, R Tkachuk, A Chu, YS Qian, J Macrander, A AF Khachatryan, R Tkachuk, A Chu, YS Qian, J Macrander, A BE MacDonald, CA Macrander, AT Ishikawa, T Morawe, C Wood, JL TI Open-faced Z-shaped channel-cut x-ray monochromator SO X-RAY SOURCES AND OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray Sources and Optics CY AUG 02-03, 2004 CL Denver, CO SP SPIE DE polished channel-cut monochromator; silicon; high-resolution x-ray topography AB Channel-cut monochromators can be easily incorporated in high-resolution image techniques. However, polishing on the inner diffracting surfaces is difficult because of blockage by the opposite face. To address this difficulty, an open-faced monolithic monochromator has been designed, produced and tested using x-rays at the Advanced Photon Source (APS). The open-faced channel cut has a "Z"-shape geometry with a hole in the mid section to allow passage of the diffracted beam. The open geometry allowed chemical mechanical polishing so that an optically smooth finish on both surfaces was achieved. The high-resolution x-ray imaging and topography measurements revealed that the new design introduces significantly less distortions in the phase-contrast images compared with conventional channel-cut monochromators produced using etching alone. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Khachatryan, R (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 7 TC 5 Z9 5 U1 2 U2 5 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5475-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5537 BP 171 EP 176 DI 10.1117/12.562377 PG 6 WC Optics SC Optics GA BBJ12 UT WOS:000225736100019 ER PT S AU Li, YM Khounsary, A Narayanan, S Macrander, A Khachatryan, R Lurio, L AF Li, YM Khounsary, A Narayanan, S Macrander, A Khachatryan, R Lurio, L BE MacDonald, CA Macrander, AT Ishikawa, T Morawe, C Wood, JL TI Design and analysis of a cooled Z-shaped germanium x-ray monochromator SO X-RAY SOURCES AND OPTICS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on X-Ray Sources and Optics CY AUG 02-03, 2004 CL Denver, CO SP SPIE DE monochromator; x-ray; germanium; design; finite element; polishing AB This paper describes the design and analysis of a contact-cooled channel-cut germanium monochromator for use on a high-heat-load x-ray beamline. This channel-cut monochromator is designed in the shape of a "Z" so that polishing the diffraction surfaces is easier. The incident x-ray beam, which is reflected from a mirror at a 0.15degrees angle, diffracts from one surface of the Z-monochromator, passes through an opening, and diffracts from the second surface. The monochromator is located 60 meters from the undulator x-ray source. The normal heat flux of the incident beam can be up to 7 W/mm(2). Thermal and structural analyses are presented, and the deformation caused by gravity is considered. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Li, YM (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 3 TC 3 Z9 3 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-5475-3 J9 P SOC PHOTO-OPT INS PY 2004 VL 5537 BP 189 EP 192 DI 10.1117/12.564241 PG 4 WC Optics SC Optics GA BBJ12 UT WOS:000225736100022 ER PT S AU Mueller, M Madejski, G Done, C Zycki, P AF Mueller, M Madejski, G Done, C Zycki, P BE Kaaret, P Lamb, FK Swank, JH TI The x-ray variability of NGC 4945: Characterizing the power spectrum through light curve simulations SO X-RAY TIMING 2003: ROSSI AND BEYOND SE AIP CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT Conference on X-Ray Timing 2003 - Rossi and Beyond CY NOV 03-05, 2003 CL Cambridge, MA SP Harvard Smithsonian Ctr Astrophys, Smithsonian Astrophys Observ, NASA, Goddard Space Sfight Ctr, Lab High Energy Astrophys, Rossi X Ray Timing Explorer Project ID DENSITY SPECTRUM; SPACED DATA; GALAXY; NGC-4151 AB For light curves sampled on an uneven grid of observation times, the shape of the power density spectrum (PDS) includes severe distortion effects due to the window function, and simulations of light curves are indispensable to recover the true PDS. We present an improved method for comparing light curves generated from a PDS model to the measured data and apply it to a 50-day long RXTE observations of NGC 4945, a Seyfert 2 galaxy with well-determined mass from megamaser observations. The improvements over previously reported investigations include the adjustment of the PDS model normalization for each simulated light curve in order to directly investigate how well the chosen PDS shape describes the source data. We furthermore implement a robust goodness-of-fit measure that does not depend on the form of the variable used to describe the power in the periodogram. We conclude that a knee-type function (smoothly broken power law) describes the data better than a simple power law; the best-fit break frequency is similar to10(-6) Hz. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. RP Mueller, M (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA. RI done, chris/D-4605-2016 OI done, chris/0000-0002-1065-7239 NR 18 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0193-4 J9 AIP CONF PROC PY 2004 VL 714 BP 190 EP 193 PG 4 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BAP36 UT WOS:000223117800035 ER PT S AU Mauche, CW AF Mauche, CW BE Kaaret, P Lamb, FK Swank, JH TI Optical, UV, and EUV oscillations of SS Cygni in outburst SO X-RAY TIMING 2003: ROSSI AND BEYOND SE AIP Conference Proceedings LA English DT Proceedings Paper CT Conference on X-Ray Timing 2003 - Rossi and Beyond CY NOV 03-05, 2003 CL Cambridge, MA SP Harvard Smithsonian Ctr Astrophys, Smithsonian Astrophys Observ, NASA, Goddard Space Sfight Ctr, Lab High Energy Astrophys, Rossi X Ray Timing Explorer Project ID QUASI-PERIODIC OSCILLATIONS; DWARF NOVA OSCILLATIONS; UX-URSAE MAJORIS; X-RAY BINARIES; EXTREME-ULTRAVIOLET FLUX; CATACLYSMIC VARIABLES; COHERENT OSCILLATIONS; RAPID OSCILLATIONS; NEUTRON-STAR; DQ-HERCULIS AB provide a review of observations in the optical, UV (HST), and EUV (EWE and Chandra LETG) of the rapid periodic oscillations of nonmagnetic, disk-accreting, high mass-accretion rate cataclysmic variables (CVs), with particular emphasis on the dwarf nova SS Cyg in outburst. In addition, I drawn attention to a correlation, valid over nearly six orders of magnitude in frequency, between the frequencies of the quasi-periodic oscillations (QPOs) of white dwarf, neutron star, and black hole binaries. This correlation identifies the high frequency quasi-coherent oscillations (so-called "dwarf nova oscillations") of CVs with the kilohertz QPOs of low mass X-ray binaries (LMXBs), and the low frequency and low coherence QPOs of CVs with the horizontal branch oscillations (or the broad noise component identified as such) of LMXBs. Assuming that the same mechanisms produce the QPOs of white dwarf, neutron star, and black hole binaries, this correlation has important implications for QPO models. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mauche, CW (reprint author), Lawrence Livermore Natl Lab, L-473,7000 E Ave, Livermore, CA 94550 USA. EM mauche@cygnus.llnl.gov NR 35 TC 1 Z9 1 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0094-243X BN 0-7354-0193-4 J9 AIP CONF PROC PY 2004 VL 714 BP 315 EP 322 PG 8 WC Astronomy & Astrophysics; Instruments & Instrumentation SC Astronomy & Astrophysics; Instruments & Instrumentation GA BAP36 UT WOS:000223117800058 ER PT J AU Hittinger, JAF Roe, PL AF Hittinger, JAF Roe, PL TI Asymptotic analysis of the Riemann problem for constant coefficient hyperbolic systems with relaxation SO ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK LA English DT Article DE asymptotic analysis; hyperbolic systems; relaxing flow; Riemann problem ID STIFF SOURCE TERMS; CONSERVATION-LAWS; GAS-DYNAMICS; EXPANSION; BEHAVIOR; SCHEMES AB The discontinuous Riemann initial value problem is considered for dissipative, constant coefficient hyperbolic systems with relaxation source terms. A short-time asymptotic expansion, a specialization of the results of Le Floch and Raviart [11], is constructed for the general linear system. Exact rates for the decay of the initial discontinuities are found to be in agreement with recent results from other approaches. A multiple scales analysis is used to identify the long-time asymptotic behavior. Many of the results can be exemplified in a simple model problem for which the exact solution can be found. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. Univ Michigan, Dept Aerosp Engn, WM Keck Lab Computat Fluid Dynam, Ann Arbor, MI 48109 USA. RP Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. EM hittinger1@llnl.gov NR 21 TC 1 Z9 1 U1 0 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 101161, 69451 WEINHEIM, GERMANY SN 0044-2267 J9 Z ANGEW MATH MECH JI Z. Angew. Math. Mech. PY 2004 VL 84 IS 7 BP 452 EP 471 DI 10.1002/zamm.200310114 PG 20 WC Mathematics, Applied; Mechanics SC Mathematics; Mechanics GA 837IE UT WOS:000222621500003 ER PT J AU Egami, T AF Egami, T TI Local crystallography of crystals with disorder SO ZEITSCHRIFT FUR KRISTALLOGRAPHIE LA English DT Article ID PULSED-NEUTRON-DIFFRACTION; ELECTRON-LATTICE INTERACTION; X-RAY-SCATTERING; ATOMIC-STRUCTURE; RELAXOR FERROELECTRICITY; POWDER-DIFFRACTION; TL2BA2CACU2O8; DISTORTIONS; MANGANITES; MECHANISM AB The assumption of perfect periodicity in the crystal lattice is the most basic tenet of crystallography. However, many materials are not crystalline. Even when they are the atomic structure of real materials is often less than perfectly periodic, and usually deviations from perfect periodicity have significant effects on their properties. Thus in order to characterize the structure of real materials by diffraction the crystallographic approaches need to be complemented by other methods focusing on disorder. B. E. Warren was a pioneer of such alternative, non-crystallographic approaches, including the method of atomic pair-density function (PDF) analysis. With the advent of synchrotron based radiation sources, such as pulsed neutron sources and synchrotron radiation sources, it recently became possible to apply the PDF technique on crystals with and without disorder, covering the whole spectrum of structural order and disorder. Here some of the recent progresses in this approach made in my research group are reviewed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, South Coll, Knoxville, TN 37996 USA. RP Egami, T (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. EM Egami@utk.edu NR 56 TC 7 Z9 7 U1 0 U2 7 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0044-2968 J9 Z KRISTALLOGR JI Z. Kristall. PY 2004 VL 219 IS 3 BP 122 EP 129 DI 10.1524/zkri.219.3.122.29092 PG 8 WC Crystallography SC Crystallography GA 819QL UT WOS:000221329600003 ER PT J AU Proffen, T Page, KL AF Proffen, T Page, KL TI Obtaining structural information from the atomic pair distribution function SO ZEITSCHRIFT FUR KRISTALLOGRAPHIE LA English DT Article ID LOCAL-STRUCTURE; SCATTERING; REFINEMENT; DISORDER; PROGRAM AB The knowledge of the detailed atomic structure of modem materials is the key to understanding the their macroscopic properties. The atomic pair distribution function (PDF) reveals short-range and medium-range structural information. In this paper we present an overview of refinement and modelling techniques. In short, we will be trying to answer the question: What can I learn from my PDF? C1 Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Proffen, T (reprint author), Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, MS H805, Los Alamos, NM 87545 USA. EM tproffen@lanl.gov RI Page, Katharine/C-9726-2009; Lujan Center, LANL/G-4896-2012; Proffen, Thomas/B-3585-2009 OI Page, Katharine/0000-0002-9071-3383; Proffen, Thomas/0000-0002-1408-6031 NR 19 TC 12 Z9 12 U1 0 U2 13 PU OLDENBOURG VERLAG PI MUNICH PA LEKTORAT MINT, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0044-2968 J9 Z KRISTALLOGR JI Z. Kristall. PY 2004 VL 219 IS 3 BP 130 EP 135 DI 10.1524/zkri.219.3.130.29100 PG 6 WC Crystallography SC Crystallography GA 819QL UT WOS:000221329600004 ER PT J AU Sinha, SK AF Sinha, SK TI Synchrotron studies of lattice distortions and lattice modulations in complex oxides SO ZEITSCHRIFT FUR KRISTALLOGRAPHIE LA English DT Article ID POLARON FORMATION; X-RAY; SUPERCONDUCTORS; MAGNETORESISTANCE; LA1-XSRXMNO3; MANGANITES; YBA2CU3OZ; PHASE; SPINS; RANGE AB We review some recent studies of lattice modulations and lattice distortions in single crystals of the layered manganite compound La1.2Sr1.8Mn2O7 and the YBa2Cu3O6+x cuprate superconductors obtained from X-ray diffuse scattering using synchrotron radiation. These results confirm the existence of a polaronic liquid (with short-range order) in the paramagnetic insulator phase of the manganite compound, and of lattice modulations (with short-range order) in the cuprate compounds, which coexist with superconductivity down to the lowest temperatures. C1 Univ Calif San Diego, La Jolla, CA 92093 USA. Los Alamos Natl Lab, LANSCE Div, Los Alamos, NM 87545 USA. RP Sinha, SK (reprint author), Univ Calif San Diego, La Jolla, CA 92093 USA. EM ssinha@physics.ucsd.edu NR 31 TC 2 Z9 2 U1 0 U2 2 PU R OLDENBOURG VERLAG PI MUNICH PA LEKTORAT M/N, K BERBER-NERLINGER, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0044-2968 J9 Z KRISTALLOGR JI Z. Kristall. PY 2004 VL 219 IS 3 BP 143 EP 147 DI 10.1524/zkri.219.3.143.29096 PG 5 WC Crystallography SC Crystallography GA 819QL UT WOS:000221329600006 ER PT J AU DeSanto, P Buttrey, DJ Grasselli, RK Lugmair, CG Volpe, AF Toby, BH Vogt, T AF DeSanto, P Buttrey, DJ Grasselli, RK Lugmair, CG Volpe, AF Toby, BH Vogt, T TI Structural aspects of the M1 and M2 phases in MoVNbTeO propane ammomidation catalysts SO ZEITSCHRIFT FUR KRISTALLOGRAPHIE LA English DT Article ID SELECTIVE OXIDATION; TERNARY PHASES; ACTIVE-CENTERS; MO5O14 TYPE; OXYGEN; AMMOXIDATION; YBA2CU3O7-X; SYSTEMS; CRYSTAL; HREM AB The structures of M1 and M2 in MoVNbTeO propane ammoxidation catalysts have been solved using a combination of TEM, neutron powder diffraction, and synchrotron X-ray powder diffraction. The unit cell of M1 is Pba2 (No. 32) with a = 21.134(2) Angstrom, b = 26.658(2) Angstrom, c = 4.0146(3) Angstrom and Z = 4. The formula unit is Mo7.8V1.2NbTe0.937O28.9. The unit cell of M2 is Pmm2 (No. 25) with a = 12.6294(6) Angstrom, b = 7.29156(30) Angstrom, c = 4.02010(7) Angstrom and Z = 4. The formula Unit is Mo4.31V1.36Te1.81Nb0.33O19.81. Tellurium sites in hexagonal channels of both phases are displaced toward vanadium-occupied framework sites, whereas Te in the heptagonal channel of M1 is near the channel center. The chemical topology resulting from oxidation states and Madelung site potentials presents active moieties for the ammoxidation of propane in M1 and propene in M2. EPR confirmed the presence of V4+ and possibly Mo5+ in M1 and V4+ in M2. C1 Univ Delaware, Dept Chem Engn, Ctr Catalyt Sci & Technol, Newark, DE 19716 USA. Symyx Technol Inc, Catalysis Grp, Santa Clara, CA 95051 USA. Natl Inst Stand & Technol, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, Ctr Funct Nanonmat, Upton, NY 11973 USA. RP Buttrey, DJ (reprint author), Univ Delaware, Dept Chem Engn, Ctr Catalyt Sci & Technol, Newark, DE 19716 USA. EM buttrey@che.udel.edu RI Vogt, Thomas /A-1562-2011; Toby, Brian/F-3176-2013 OI Vogt, Thomas /0000-0002-4731-2787; Toby, Brian/0000-0001-8793-8285 NR 32 TC 147 Z9 147 U1 0 U2 17 PU R OLDENBOURG VERLAG PI MUNICH PA LEKTORAT M/N, K BERBER-NERLINGER, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0044-2968 J9 Z KRISTALLOGR JI Z. Kristall. PY 2004 VL 219 IS 3 BP 152 EP 165 DI 10.1524/zkri.219.3.152.29091 PG 14 WC Crystallography SC Crystallography GA 819QL UT WOS:000221329600008 ER PT J AU Baker, SM Kolthammer, WS Tan, JB Smith, GS AF Baker, SM Kolthammer, WS Tan, JB Smith, GS TI Nanoporous thin films and porous inorganic substrates for lipid bilayer support materials SO ZEITSCHRIFT FUR KRISTALLOGRAPHIE LA English DT Article ID MICROMACHINED SUPPORTS; NEUTRON REFLECTOMETRY AB Synthetic lipid bilayers are excellent mimics of cell membranes. In order to experimentally access these thin layers and oriented proteins in membranes, suitable supports which allow for membrane fluidity while assuring membrane stability need to be developed. Nanoporous polymer templates created from the natural phase segregation of immiscible diblock copolymers are uniform arrays with pore sizes naturally on the scale of macromolecules, tens of nanometers, and grain sizes currently on the order of microns. We study the Suitability of such templates, appropriately treated to present a hydrophilic surface, as substrates for lipid bilayers with scanning force microscopy and neutron reflectometry. In the process, we use tip deflection curves to establish simple criteria for determining the presence of a lipid layer on the substrates. Gold coated porous polymers and silicon oxide templates in silicon both appear to be suitable support materials. C1 Harvey Mudd Coll, Dept Chem, Claremont, CA 91711 USA. Oak Ridge Natl Lab, HFIR Ctr Neutron Scattering, Oak Ridge, TN 37831 USA. RP Baker, SM (reprint author), Harvey Mudd Coll, Dept Chem, 301 E 12th St, Claremont, CA 91711 USA. EM shenda-baker@hmc.edu RI Smith, Gregory/D-1659-2016 OI Smith, Gregory/0000-0001-5659-1805 NR 21 TC 5 Z9 6 U1 0 U2 7 PU R OLDENBOURG VERLAG PI MUNICH PA LEKTORAT M/N, K BERBER-NERLINGER, POSTFACH 80 13 60, D-81613 MUNICH, GERMANY SN 0044-2968 J9 Z KRISTALLOGR JI Z. Kristall. PY 2004 VL 219 IS 3 BP 179 EP 185 DI 10.1524/zkri.219.3.179.29090 PG 7 WC Crystallography SC Crystallography GA 819QL UT WOS:000221329600011 ER PT J AU Yu, H Li, JB Loomis, RA Gibbons, PC Wang, LW Buhro, WE AF Yu, H Li, JB Loomis, RA Gibbons, PC Wang, LW Buhro, WE TI Cadmium selenide quantum wires and the transition from 3D to 2D confinement SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID LIQUID-SOLID GROWTH; CDSE NANOCRYSTALS; RODS; NANOWIRES; ENERGY; DOTS C1 Washington Univ, Dept Chem, St Louis, MO 63130 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Lawrence Berkeley Natl Lab, Computat Res Div, Berkeley, CA 94720 USA. RP Wang, LW (reprint author), Washington Univ, Dept Chem, St Louis, MO 63130 USA. EM lwwang@lbl.gov; buhro@wuchem.wustl.edu RI Buhro, William/A-7682-2009 NR 16 TC 241 Z9 244 U1 5 U2 63 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD DEC 31 PY 2003 VL 125 IS 52 BP 16168 EP 16169 DI 10.1021/ja037971+ PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 757RG UT WOS:000187574800006 PM 14692740 ER PT J AU Weber, ER AF Weber, ER TI Understanding defects in semiconductors as key to advancing device technology SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE defect identification; device performance; deep levels; hydrogenic levels; Si-native defects; Si-diffusion; Si-transition metals; Si-gettering; DX centers; antisite defects/EL2 ID MOLECULAR-BEAM EPITAXY; ARSENIC-ANTISITE DEFECT; TEMPERATURE-GROWN GAAS; 0.82-EV ELECTRON TRAP; LIGHT-EMITTING-DIODES; CRYSTALLINE SILICON; SWIRL DEFECTS; POINT-DEFECTS; PHOSPHORUS-DIFFUSION; SURFACE PASSIVATION AB The process of understanding defects in semiconductors that are relevant for device technologies is briefly reviewed. Examples of such defects in silicon, GaAs, GaN and related alloys are discussed. These examples include the study of native defects and self-diffusion in silicon, transition metals in silicon, transition metal gettering, hydrogen in silicon, DX-centers in compound semiconductors, EL2, the arsenic antisite defect in GaAs, and defects in GaN and related alloys. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Mat Sci & Engn, 374 Hearst Min Bldg, Berkeley, CA 94720 USA. EM weber@socrates.berkeley.edu RI Schaff, William/B-5839-2009 NR 106 TC 21 Z9 21 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 1 EP 14 DI 10.1016/j.physb.2003.10.001 PG 14 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200002 ER PT J AU Yu, KM Wu, J Walukiewicz, W Shan, W Beeman, JW Mars, DE Chamberlin, DR Scarpulla, MA Dubon, OD Ridgway, MC Geisz, JF AF Yu, KM Wu, J Walukiewicz, W Shan, W Beeman, JW Mars, DE Chamberlin, DR Scarpulla, MA Dubon, OD Ridgway, MC Geisz, JF TI Mutual passivation of group IV donors and isovalent nitrogen in diluted GaNxAs1-x alloys SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE mutual passivation; diluted nitride; band anticrossing; band gap reduction ID BAND-GAP ENERGY; GAAS; SEMICONDUCTORS; SULFUR AB We demonstrate the mutual passivation of electrically active group IV donors and isovalent N atoms in the GaNxAs1-x alloy system. This phenomenon occurs through the formation of a donor-nitrogen bond in the nearest neighbor IVGa-N-As pairs. In Si-doped GaInN0.017As0.983 the electron concentration starts to decrease rapidly at an annealing temperature of 700degreesC from similar to3 x 10(19)cm(-3) in the as-grown state to less than 10(16)cm(-3) after an annealing at 900(degrees) for 10s. At the same time, annealing of this sample at 950degreesC increases the gap by about 35meV, corresponding to a reduction of the concentration of the active N atoms by an amount very close to the total Si concentration. We also show that the formation of Si-Ga-N-As pairs is controlled by the diffusion of Si via Ga vacancies to the nearest N-As Site. The general nature of this mutual passivation effect is confirmed by our study of Ge-doped GaNxAs1-x layers formed by N and Ge co-implantation in GaAs followed by pulsed laser melting. Published by Elsevier B.V. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Agilent Labs, Palo Alto, CA 94304 USA. Australian Natl Univ, Canberra, ACT, Australia. Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RP Lawrence Berkeley Natl Lab, 1 Cyclotron Rd MS2-200, Berkeley, CA 94720 USA. EM kmyu@lbl.gov RI Scarpulla, Michael/C-7941-2009; Yu, Kin Man/J-1399-2012; Ridgway, Mark/D-9626-2011; Wu, Junqiao/G-7840-2011; OI Yu, Kin Man/0000-0003-1350-9642; Ridgway, Mark/0000-0002-0642-0108; Wu, Junqiao/0000-0002-1498-0148; Scarpulla, Michael/0000-0002-6084-6839 NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 389 EP 393 DI 10.1016/j.physb.2003.09.060 PG 5 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200076 ER PT J AU Reshchikov, MA Jasinski, J Liliental-Weber, Z Huang, D He, L Visconti, P Morkoc, H AF Reshchikov, MA Jasinski, J Liliental-Weber, Z Huang, D He, L Visconti, P Morkoc, H TI Photoluminescence from structural defects in GaN SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE GaN; photoluminescence; structural defects ID MOLECULAR-BEAM EPITAXY; DISLOCATIONS; PARAMETERS; SILICON AB We studied optical manifestation of structural defects in unintentionally doped GaN. A series of sharp peaks (labeled as Y-i with i = 1,2,...,l 1) was observed in the low-temperature photoluminescence spectrum in the photon energy range between 2.6 and 3.46eV. We attribute the majority of these peaks to excitons bound to yet unidentified structural defects. A preliminary transmission electron microscopy study in one of the samples exhibiting strong Y-i lines revealed numerous inclusions, presumably inversion domains, which may be responsible for at least some of the Y-i lines. (C) 2003 Elsevier B.V. All rights reserved. C1 Virginia Commonwealth Univ, Dept Elect Engn, Richmond, VA 23284 USA. Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA. CNR, Inst Studio Nuovi Mat Elettron, I-73100 Lecce, Italy. Fudan Univ, Dept Phys, Shanghai 200433, Peoples R China. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Reshchikov, MA (reprint author), Virginia Commonwealth Univ, Dept Elect Engn, 601 W Main St, Richmond, VA 23284 USA. EM mreshchi@vcu.edu RI Liliental-Weber, Zuzanna/H-8006-2012; VISCONTI, PAOLO/L-7214-2015 OI VISCONTI, PAOLO/0000-0002-4058-4042 NR 11 TC 12 Z9 13 U1 3 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 440 EP 443 DI 10.1016/j.physb.2003.09.030 PG 4 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200087 ER PT J AU Pintilie, I Fretwurst, E Kramberger, G Lindstroem, G Li, Z Stahl, J AF Pintilie, I Fretwurst, E Kramberger, G Lindstroem, G Li, Z Stahl, J TI Second-order generation of point defects in highly irradiated float zone silicon - annealing studies SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE annealing of point defects; divacancy-oxygen complex; TSC ID VACANCY-OXYGEN COMPLEXES; DIODES; EPR AB Isothermal and isochronal annealing experiments have shown that the I defect (the main cause for the changes in silicon diodes characteristics after high levels of gamma-irradiation) is stable up to 325-350degreesC. Possible reactions, which can explain the behavior of different defects formed during the annealing experiments, are discussed. All the experimental results concerning the I center (second-order irradiation induced defect, formed most likely via VO center, suppressed in oxygen rich material, high thermal stability) make it the favorite for being associated with the V(2)O(2) complex. (C) 2003 Elsevier B.V. All rights reserved. C1 Natl Inst Mat Phys, Bucharest 76900, Magurele, Romania. Univ Hamburg, Inst Phys Expt, D-22761 Hamburg, Germany. DESY, Deutsch Elektronen Synchrotron, D-2000 Hamburg, Germany. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Pintilie, I (reprint author), Natl Inst Mat Phys, POB MG-7,Atomistilor 105 Bis, Bucharest 76900, Magurele, Romania. EM ioana@alpha1.infim.ro RI Pintilie, Ioana/C-4545-2011 NR 12 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 578 EP 582 DI 10.1016/j.physb.2003.09.131 PG 5 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200118 ER PT J AU Scarpulla, MA Daud, U Yu, KM Monteiro, O Liliental-Weber, Z Zakharov, D Walukiewicz, W Dubon, OD AF Scarpulla, MA Daud, U Yu, KM Monteiro, O Liliental-Weber, Z Zakharov, D Walukiewicz, W Dubon, OD TI Diluted magnetic semiconductors formed by ion implantation and pulsed-laser melting SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE GaMnAs; GaMnP; laser processing; ion implantation; diluted magnetic semiconductor ID MOLECULAR-BEAM EPITAXY; CURIE-TEMPERATURE; FERROMAGNETIC GA1-XMNXAS; GAAS; GAMNAS AB Using ion implantation followed by pulsed-laser melting (PLM), we have synthesized ferromagnetic films of Ga1-xMnxAs. Ion-channeling experiments reveal that these films are single crystalline and have high Mn substitutionality while variable temperature resistivity measurements reveal the strong Mn-hole interactions characteristic of carrier-mediated ferromagnetism in homogeneous Diluted magnetic semiconductors. We have observed Curie temperatures (T(C)s) of approximately 80 K for films with substitutional Mn concentrations of x = 0.04. The use of n-type counter doping as a means of increasing Mn substitutionality and T-C is explored by co-implantation of Mn and Te into GaAs. In Ga1-xMnxP samples synthesized using our technique, the implanted layer regrows as an epitaxial single crystal capped by a highly defective surface layer. These samples display ferromagnetism with T-C approximate to 23 K. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Mat Sci & Engn, 180 HMMB, Berkeley, CA 94720 USA. EM scarps@newton.berkeley.edu RI Scarpulla, Michael/C-7941-2009; Liliental-Weber, Zuzanna/H-8006-2012; Yu, Kin Man/J-1399-2012; Zakharov, Dmitri/F-4493-2014; OI Yu, Kin Man/0000-0003-1350-9642; Scarpulla, Michael/0000-0002-6084-6839 NR 20 TC 22 Z9 22 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 EI 1873-2135 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 908 EP 912 DI 10.1016/j.physb.2003.09.113 PG 5 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200190 ER PT J AU Beckman, SP Chrzan, DC AF Beckman, SP Chrzan, DC TI Dislocation cores and their electronic states: partial dislocations in GaAs SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE GaAs; dislocations; DOS; reconstruction ID TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; SEMICONDUCTORS AB The electronic structures, as predicted by the local density approximation, of the glide set partial dislocations in GaAs are presented. The calculation reveal mid-gap states for both the 90degrees and 30degrees alpha-type partials, whereas the beta-cores reveal states only slightly above the valance band energy. (C) 2003 Published by Elsevier B.V. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Chrzan, DC (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, 210 Hearst Mem Min Bldg, Berkeley, CA 94720 USA. EM dcchrzan@socrates.berkeley.edu NR 12 TC 11 Z9 11 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 1001 EP 1004 DI 10.1016/j.physb.2003.09.189 PG 4 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200210 ER PT J AU Zhang, P Vainola, H Istratov, AA Weber, ER AF Zhang, P Vainola, H Istratov, AA Weber, ER TI The thermal stability of iron precipitates in silicon after internal gettering SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 22nd International Conference on Defects in Semiconductors (ICDS-22) CY JUL 28-AUG 01, 2003 CL UNIV AARHUS, AARHUS, DENMARK HO UNIV AARHUS DE internal gettering; re-dissolution energy barrier; iron; silicon ID TECHNOLOGY; WAFER AB The re-dissolution behavior of iron gettered at oxide precipitates serving as internal gettering sites was studied in the temperature range from 750degreesC to 900degreesC using p-type Czochralski-grown silicon with a boron doping level of 2.5 x 10(14) cm(-3) and oxide precipitates density of 5 x 10(9) cm(-3). The concentration of interstitial iron and iron-boron pairs was measured by deep-level transient spectroscopy. It was found that the re-dissolved iron concentration can be fitted by an exponential dependence, and the dissolution rate tau(-1) had an Arrhenius-type dependence on temperature. The activation energy of the dissolution time constant was found to be 1.47 eV. Considering the activation energy of 0.67 eV for iron diffusion in silicon, our result implies an effective binding energy of 0.80 eV between gettered iron impurities and oxide precipitates. The re-dissolved iron concentration during different heat treatments was simulated with our gettering simulator taking into account this effective binding energy. (C) 2003 Published by Elsevier B.V. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Helsinki Univ Technol, Electron Phys Lab, FIN-02015 Helsinki, Finland. RP Zhang, P (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, MS 62R0203,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM pzhang@lbl.gov RI Savin, Hele/E-5155-2012 OI Savin, Hele/0000-0003-3946-7727 NR 17 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC 31 PY 2003 VL 340 BP 1051 EP 1055 DI 10.1016/j.physb.2003.09.205 PG 5 WC Physics, Condensed Matter SC Physics GA 765TR UT WOS:000188300200221 ER EF