A5024720795- High-pressure geophysics and materials
- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Nuclear Physics and Applications
- Electromagnetic Launch and Propulsion Technology
- Diamond and Carbon-based Materials Research
- Laser Material Processing Techniques
- High-Velocity Impact and Material Behavior
- Energetic Materials and Combustion
- Advanced X-ray Imaging Techniques
- Atomic and Molecular Physics
- X-ray Diffraction in Crystallography
- X-ray Spectroscopy and Fluorescence Analysis
- Force Microscopy Techniques and Applications
- Metal and Thin Film Mechanics
- Advanced Fiber Laser Technologies
- Ion-surface interactions and analysis
- Microstructure and mechanical properties
- Astro and Planetary Science
- Chalcogenide Semiconductor Thin Films
- Crystallography and Radiation Phenomena
- Parallel Computing and Optimization Techniques
- Machine Learning in Materials Science
- Laser-Matter Interactions and Applications
- Combustion and Detonation Processes
Sandia National Laboratories
2014-2024
Yunnan Normal University
2024
Sandia National Laboratories California
2013-2023
John Wiley & Sons (United Kingdom)
2023
University of Oxford
2023
Hudson Institute
2023
John Wiley & Sons (United States)
2023
University of New Mexico
2020
Office of Scientific and Technical Information
2010-2012
National Technical Information Service
2010-2012
Pulsed power accelerators compress electrical energy in space and time to provide versatile experimental platforms for high density inertial confinement fusion science. The 80-TW “Z” pulsed facility at Sandia National Laboratories is the largest device world today. Z discharges up 22 MJ of stored its capacitor banks into a current pulse that rises 100 ns peaks as 30 MA low-inductance cylindrical targets. Considerable progress has been made over past 15 years use precision scientific tool....
Time-resolved x-ray diffraction (XRD) of compressed liquid water shows transformation to ice VII in 6 nsec, revealing crystallization rather than amorphous solidification during compression freezing. Application classical nucleation theory indicates heterogeneous and one-dimensional (e.g., needlelike) growth. These first XRD data demonstrate rapid growth kinetics with implications for fundamental physics diffusion-mediated thermodynamic modeling collision or impact events on ice-rich...
We report on a single-state measurement of electrical conductivity warm dense gold in the solid to plasma transition regime. This is achieved using idealized slab approach isochoric heating ultrathin samples by femtosecond laser, coupled with probe measurements reflectivity and transmission. The experiment also reveals time scale associated disassembly laser heated solid.
An open question about the dynamical behavior of materials is how phase transition occurs in highly nonequilibrium systems. One important class study excitation a solid by an ultrafast, intense laser. The preferential heating electrons laser field gives rise to initial states dominated hot cold lattice. Using femtosecond pump-probe approach, we have followed temporal evolution optical properties such system. results show interesting correlation nonthermal melting and lattice disordering...
Veloce is a medium-voltage, high-current, compact pulsed power generator developed for isentropic and shock compression experiments. Because of its increased availability ease operation, well suited studying experiments (ICE) in much greater detail than previously allowed with larger machines such as the Z accelerator. Since technology used dynamic material has not been used, it necessary to examine several key issues ensure that accurate results are obtained. In present experiments, panel...
A magnetic loading technique was used to study the strength of pure, annealed, and cold-rolled polycrystalline tantalum under planar ramp at strain rates ∼106/s. Both initial yield flow after compression peak stresses 18 GPa were determined. For sample thicknesses ranging from 0.5–6.0 mm, it found that elastic limit ∼3.2 GPa, corresponding a 1.6 for annealed Ta sharply defined essentially independent thickness. After yielding, relaxation longitudinal stress occurred greater than ∼0.5...
Understanding structural stability and phase transformation of nanoparticles under high pressure is great scientific interest, as it one the crucial factors for design, synthesis, application materials. Even though high-pressure research on nanomaterials has been widely conducted, their shape-dependent transition behavior still remains unclear. Examples transitions CdS are very limited, despite fact that most studied wide band gap semiconductors. Here we have employed in situ synchrotron...
The application of a space-resolving spectrometer to X-ray Thomson Scattering (XRTS) experiments has the potential advance study warm dense matter. This motivated design spherical crystal spectrometer, which is doubly focusing geometry with an overall high sensitivity and capability providing high-resolution, space-resolved spectra. A detailed analysis image fluence throughput in this carried out analytical estimates these quantities are presented. informed new intended for future XRTS on...
A magnetic loading technique was used to ramp load single-crystal [100] lithium fluoride specimens peak stresses of 5–114 GPa. Wave analysis in situ particle velocity profiles estimate the compressive strength LiF at stress. It found that increased with stress and showed two distinct regions hardening; first is believed be governed by strain hardening second pressure hardening. The quasielastic obtained from initial part unloading shown saturate about 1.3% for greater than approximately 30...
Abstract Gold nanostructured materials exhibit important size- and shape-dependent properties that enable a wide variety of applications in photocatalysis, nanoelectronics phototherapy. Here we show the use superfast dynamic compression to synthesize extended gold nanostructures, such as nanorods, nanowires nanosheets, with nanosecond coalescence times. Using pulsed power generator, ramp compress spherical nanoparticle arrays pressures tens GPa, demonstrating pressure-driven assembly beyond...
An abrupt change in energy transport has been observed femtosecond laser heated gold when the absorbed flux exceeds ~7×10(12) W/cm(2). Below this value, is carried by ballistic motion of nonthermal electrons produced interband excitation. Above value appears to include and heat diffusion thermalized hot electrons. The component limited a This offers unique benchmark for comparison with theory on nonequilibrium electron transport.
A magnetic loading technique was used to ramp load pure aluminum and 6061 alloy peak stresses of approximately 29GPa. The rate 106∕s, followed by unloading from stress at a about 105∕s. samples had impurity levels ranging 10ppmto0.5wt% average grain sizes in the range 144–454μm. prepared either T6 condition with 5–50μm, or T0 heat treatment size 40μm. wave profile estimate compressive strength during unloading. It found that estimated increased for all materials change insensitive initial...
A magnetic loading technique was used to produce planar ramp of [100] and [110] orientations single crystal tantalum peak stresses either ∼18 or ∼86 GPa for applied plastic strain rates about 2 × 106/s. It found that the dynamic elastic limit varied only slightly factor-of-2 changes in resulting near 5 105/s. For wave propagation direction, from 4.18–3.92 corresponding sample thicknesses 0.625–1.030 mm exhibited a slight rate dependence region studied. compression, essentially independent...
In a previous study by Asay et al. [J. Appl. Phys. 106, 073515 (2009)], the inelastic response of annealed and cold-rolled pure polycrystalline tantalum at intermediate strain rates was characterized with ramp wave loading to peak longitudinal stresses 17 GPa. It found that Ta about 106/s exhibited pronounced elastic overshoot, followed rapid stress relaxation amplitude precursor depicted essentially no dependence on sample thickness for samples controlled initial properties, in contrast...
Recently, warm dense matter has emerged as an interdisciplinary field that draws increasing interest in plasma physics, condensed high pressure science, astrophysics, inertial confinement fusion, well material science under extreme conditions. To allow the study of well-defined states, we introduced concept idealized slab (ISP) can be realized laboratory via (1) isochoric heating a solid and (2) propagation shock wave solid. The application this provides new means for probing AC...
The high-pressure response of titanium dioxide (${\mathrm{TiO}}_{2}$) is interest because its numerous industrial applications and structural similarities to silica (${\mathrm{SiO}}_{2}$). We used three platforms---Sandia's Z machine, Omega Laser Facility, density-functional theory-based quantum molecular dynamics (QMD) simulations---to study the equation state (EOS) ${\mathrm{TiO}}_{2}$ at extreme conditions. magnetically accelerated flyer plates Sandia measure Hugoniot up pressures 855...
We report here pressure induced nanocrystal coalescence of ordered lead chalcogenide arrays into one-dimensional (1D) and 2D nanostructures. In particular, atomic crystal phase transitions mesoscale PbS PbSe nanocrystals have been observed monitored in situ respectively by wide- small-angle synchrotron X-ray scattering techniques. At the scale, both underwent reversible structural transformations from cubic to orthorhombic at significantly higher pressures than those for corresponding bulk...
Titanium alloys are used in a large array of applications. In this work we focus our attention on the most alloy, Ti-6Al-4V (Ti64), which has excellent mechanical and biocompatibility properties with applications aerospace, defense, biomedical, other fields. Here present high-fidelity experimental shock compression data measured Sandia's Z machine. We extend principal Hugoniot for Ti64 to more than threefold compression, up over 1.2 TPa. use validate ab initio molecular dynamics simulations...
We have developed a conceptual design of next-generation pulsed-power accelerator that is optimized for megajoule-class dynamic-material-physics experiments. Sufficient electrical energy delivered by the to physics load achieve---within centimeter-scale samples---material pressures as high 1 TPa. The based on an architecture founded three concepts: single-stage electrical-pulse compression, impedance matching, and transit-time-isolated drive circuits. prime power source consists 600...
Abstract The outer core of the Earth is composed primarily liquid iron, and inner boundary governed by intersection melt line geotherm. While there are many studies on thermodynamic equation state for solid iron relatively unexplored. We use dynamic compression to diagnose high‐pressure utilizing shock‐ramp capability at Sandia National Laboratories’ Z‐Machine. This technique enables measurements material states off Hugoniot initially shocking samples subsequently driving a further,...