A5022017347- High-pressure geophysics and materials
- Laser-Plasma Interactions and Diagnostics
- Diamond and Carbon-based Materials Research
- Nuclear Physics and Applications
- Electromagnetic Launch and Propulsion Technology
- Advanced Chemical Physics Studies
- Energetic Materials and Combustion
- Atomic and Molecular Physics
- High-Velocity Impact and Material Behavior
- Astro and Planetary Science
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Earthquake Detection and Analysis
- Cold Fusion and Nuclear Reactions
- Metal and Thin Film Mechanics
- Geophysics and Sensor Technology
- Laser-induced spectroscopy and plasma
- Pulsed Power Technology Applications
- Magnetic confinement fusion research
- Intermetallics and Advanced Alloy Properties
- Advanced materials and composites
- Planetary Science and Exploration
- Scientific Measurement and Uncertainty Evaluation
Sandia National Laboratories
2014-2024
Sandia National Laboratories California
2004-2022
Lawrence Livermore National Laboratory
2007-2021
SLAC National Accelerator Laboratory
2021
Washington State University
1998-2020
University of New Mexico
2020
General Atomics (United States)
2016
Office of Scientific and Technical Information
2001-2009
National Technical Information Service
2001-2009
Los Alamos National Laboratory
2001-2009
Driving liquid deuterium into metal Quick and powerful compression can force materials to change their properties dramatically. Knudson et al. compressed extreme temperatures pressures using high-energy magnetic pulses at the Sandia Z-machine (see Perspective by Ackland). Deuterium began reflect like a mirror during compression, as electrical conductivity sharply increased. The observed conditions for metallization of hydrogen help us build theoretical models universe's most abundant...
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....
The Z accelerator [R. B. Spielman, W. A. Stygar, J. F. Seamen et al., Proceedings of the 11th International Pulsed Power Conference, Baltimore, MD, 1997, edited by G. Cooperstein and I. Vitkovitsky (IEEE, Piscataway, NJ, 1997), Vol. 1, p. 709] at Sandia National Laboratories delivers ∼20MA load currents to create high magnetic fields (>1000T) pressures (megabar gigabar). In a z-pinch configuration, pressure (the Lorentz force) supersonically implodes plasma created from cylindrical...
Using intense magnetic pressure, a method was developed to launch flyer plates velocities in excess of 20 km/s. This technique used perform plate-impact, shock wave experiments on cryogenic liquid deuterium ( L-D(2)) examine its high-pressure equation state. an impedance matching method, Hugoniot measurements were obtained the pressure range 30-70 GPa. The results these disagree with previously reported L-D(2) above approximately 40 GPa, but are good agreement first principles, ab initio...
The high-energy density behavior of carbon, particularly in the vicinity melt boundary, is broad scientific interest and particular to those studying planetary astrophysics inertial confinement fusion. Previous experimental data several hundred gigapascal pressure range, near have only been able provide with accuracy capable qualitative comparison theory. Here we present shock-wave experiments on carbon (using a magnetically driven flyer-plate technique an order magnitude improvement...
The high-pressure response of cryogenic liquid deuterium $(L{\mathrm{D}}_{2})$ has been studied to pressures $\ensuremath{\sim}400\mathrm{GPa}$ and densities $\ensuremath{\sim}1.5{\mathrm{g}/\mathrm{c}\mathrm{m}}^{3}.$ Using intense magnetic pressure produced by the Sandia National Laboratories $Z$ accelerator, macroscopic aluminum or titanium flyer plates, several mm in lateral dimensions a few hundred microns thickness, have launched velocities excess 22 km/s, producing constant drive...
Evaluation of models and theory high-pressure material response is largely made through comparison with shock wave data, which rely on impedance match standards. The recent use quartz as a standard has prompted need for improved data. We report here measurements the Hugoniot curve from 0.1-1.6 TPa. new in agreement our ab initio calculations, reveal substantial errors have immediate ramifications equations state deuterium, helium, carbon at pressures relevant to giant planets other...
Recently there has been tremendous increase in the number of identified extra-solar planetary systems. Our understanding their formation is tied to exoplanet internal structure models, which rely upon equations state light elements and compounds like water. Here we present shock compression data for water with unprecedented accuracy that shows commonly used modeling significantly overestimate compressibility at conditions relevant interiors. Furthermore, show its behavior these conditions,...
Lithium fluoride (LiF) is a common window material used in shock- and ramp-compression experiments because it displays host of positive attributes these applications. Most commonly, to maintain stress at an interface velocimetry techniques are record the particle velocity that interface. In this application, LiF remains transparent stresses up 200 GPa. range, has elastic-plastic response with very low (<0.5 GPa) elastic precursor exhibits no known solid-solid phase transformations....
$\ensuremath{\alpha}$-quartz has been used prolifically in recent years as an impedance matching standard the multimegabar regime (1 Mbar $=$ 100 GPa). This is due to fact that above $\ensuremath{\sim}$90--100 GPa along principal Hugoniot becomes reflective, and thus shock velocities can be measured high precision using velocity interferometry. property allows for high-precision measurements, however, accuracy of measurements depends upon knowledge both release or reshock response...
This paper explores the role of electro-thermal instabilities on dynamics magnetically accelerated implosion systems. Electro-thermal result from non-uniform heating due to temperature dependence in conductivity a material. Comparatively little is known about these types compared well Magneto-Rayleigh-Taylor (MRT) instability. We present simulations that show electrothermal form immediately after surface material conductor melts and can act as significant seed subsequent MRT instability...
A capability to produce quasi-isentropic compression of solids using pulsed magnetic loading on the Z accelerator has recently been developed and demonstrated [C. A. Hall, Phys. Plasmas 7, 2069 (2000)]. This technique allows planar, continuous materials stresses approaching 1.5 Mbar. In initial stages development, experimental configuration used a magnetically loaded material cup or disk as sample interest pressed into conductor. installation caused distortions that limited ability attach...
The intense magnetic field produced by the 20 MA Z accelerator is used as an impulsive pressure source to accelerate metal flyer plates high velocity for purpose of performing plate impact, shock wave experiments. This capability has been significantly enhanced recently developed pulse shaping Z, which enables tailoring rise time peak current a specific material and drive avoid formation within during acceleration. Consequently, full advantage can be taken available achieve maximum possible...
Hugoniot measurements were performed on aluminum (6061-T6) in the stress range of 100–500 GPa (1–5 Mbar) using a magnetically accelerated flyer plate technique. This method launch utilizes high currents, and resulting magnetic fields produced at Sandia Z Accelerator to accelerate macroscopic plates (approximately 12×25 mm lateral dimension ∼300 μm thickness) velocities excess 20 km/s. technique was used perform plate-impact shock-wave experiments determine high-stress equation state (EOS)....
Iron was ramp-compressed over timescales of 3 ≤ t(ns) 300 to study the time-dependence α→ε (bcc→hcp) phase transformation. Onset stresses (σα→ε) for transformation ∼14.8-38.4 GPa were determined through laser and magnetic ramp-compression techniques where transition strain-rate varied between 106 ≤μ̇α→ε(s−1) 5×108. We find σα→ε= 10.8 + 0.55 ln(μ̇α→ε) μ̇α→ε < 106/s 1.15(μ̇α→ε)0.18 > 106/s. This μ̇ response is quite similar recent results on incipient plasticity in Fe [Smith et...
We present shock compression data for deuterium through the molecular-to-atomic transition along principal Hugoniot with unprecedented precision, enabling discrimination between subtle differences in first-principle theoretical predictions. These observations, supported reshock measurements, provide tight constraints a regime directly relevant to planetary interiors. Our findings are best agreement density functional theory; however, no one exchange-correlation describes well both onset of...
Isentropic compression experiments (ICE) have been performed on the Z accelerator facility at Sandia National Laboratory. We describe experimental design that used large magnetic fields to slowly compress samples pressures in excess of 400 kbar. Velocity wave profile measurements were analyzed yield isentropic equations state (EOS). The method can also material strength properties. magnetohydronamic simulations and results “square short” configuration copper discuss ICE EOS with this...
A novel approach was developed to probe density compression of liquid deuterium (L-D2) along the principal Hugoniot. Relative transit times shock waves reverberating within sample are shown be sensitive due first shock. This technique has proven more than conventional method inferring from and mass velocity, at least in this high-pressure regime. Results range 22-75 GPa indicate an approximately fourfold compression, provide data differentiate between proposed theories for hydrogen its isotopes.
A technique has previously been developed on the Z accelerator [R. B. Spielman et al., Phys. Plasmas 5, 2105 (1998)] to generate ramped compression waves in condensed matter for equation-of-state studies [C. A. Hall, J. R. Asay, M. D. Knudson, W. Stygar, Spielman, T. Pointon, Reisman, Toor, and C. Cauble, Rev. Sci. Instrum. 72, 3587 (2001)] by using Lorentz force push solid electrodes rather than drive a pinch. This now extended multimegabar pressures shaping current pulse significantly...
Current pulse shaping techniques, originally developed for planar dynamic material experiments on the Z-machine [M. K. Matzen et al., Phys. Plasmas 12, 055503 (2005)], are adapted to design of controlled cylindrical liner implosions. By driving these targets with a current shape that prevents shock formation inside liner, heating is avoided along corresponding decrease in electrical conductivity ahead magnetic diffusion wave penetrating liner. This results an imploding significant amount its...
Magnetically-driven, planar shockless-compression experiments to multi-megabar pressures were performed on tantalum samples using a stripline target geometry. Free-surface velocity waveforms measured in 15 cases; nine of these dual-sample configuration with two different thicknesses opposing electrodes, and six single-sample bare electrode opposite the sample. Details are given application inverse Lagrangian analysis (ILA) data, including potential sources error. The most significant source...
We report on a new technique for obtaining off-Hugoniot pressure vs. density data solid metals compressed to extreme by magnetically driven liner implosion the Z-machine (Z) at Sandia National Laboratories. In our experiments, comprises inner and outer metal tubes. The tube is composed of sample material (e.g., Ta Cu) whose state be inferred. Al serves as current carrying cathode. Another aluminum much larger radius anode. A shaped pulse quasi-isentropically compresses it implodes. iterative...