Examination of the high pressure - temperature behavior of MgO by shock compression and first principles calculations
Abstract not provided.
Publications
Modeling experiments on Z where chemistry matters: polymers CO2 and explosives
Abstract not provided.
Priority for DCS
Abstract not provided.
Solid Liner Implosions on Z for Producing Multi-Megabar Shockless Compressions
Abstract not provided.
4th Workshop on Ramp Compression
Abstract not provided.
Simulations of Dynamic Laser/Plasma X-ray Production
IEEE Transactions on Plasma Science Special Issue on Pulsed Power Science and Technology
Abstract not provided.
Equation of state of mixtures: density functional theory (DFT) simulations and experiments on Sandia's Z machine
Abstract not provided.
Radiography of magnetically-driven implosions of initially solid beryllium cylindrical shells for equation-of-state studies at the Z pulsed-power facility
Abstract not provided.
Shock Compression of MgO
Abstract not provided.
Two-Dimensional Radiation MHD Model Assessment of Designs for Initial Argon Gas Distributions to be Imploded on the Z machine
Abstract not provided.
Equation of state for heavy gases in the warm dense matter regime: experiments on Sandia's Z accelerator and density functional theory (DFT) simulations
Abstract not provided.
Equation of state of mixtures: density functional theory (DFT) simulations and experiments on Sandia's Z machine
Abstract not provided.
Simulations of Dynamic Laser/Plasma X-ray Production
Abstract not provided.
Simulations of Dynamic Laser/Plasma X.Ray Procudtion
Abstract not provided.
Experiments to Characterize a >100 keV High-resolution X-ray Backlighter for Cylindrical Imploding Liners at the Z Machine
Abstract not provided.
Mesoscale simulation of shocked poly-(4-methyl-1-pentene) (PMP) foams
Hydrocarbon foams are commonly used in HEDP experiments, and are subject to shock compression from tens to hundreds of GPa. Modeling foams is challenging due to the heterogeneous character of the foam. A quantitative understanding of foams under strong dynamic compression is sought. We use Sandia's ALEGRA-MHD code to simulate 3D mesoscale models of pure poly(4-methyl-1-petene) (PMP) foams. We employ two models of the initial polymer-void structure of the foam and analyze the statistical properties of the initial and shocked states. We compare the simulations to multi-Mbar shock experiments at various initial foam densities and flyer impact velocities. Scatter in the experimental data may be a consequence of the initial foam inhomogeneity. We compare the statistical properties the simulations with the scatter in the experimental data.
Beryllium liner z-pinch implosions for inertial confinement fusion and dynamic materials studies at the Z pulsed-power facility
Abstract not provided.
Understanding 3D wire-array Z pinch stagnation in terms of 1D solutions
Abstract not provided.
ALEGRA modeling of gas puff Z-pinch experiments at the ZR facility
Gas puff z-pinch experiments have been proposed for the refurbished Z (ZR) facility for CY2011. Previous gas puff experiments [Coverdale et. al., Phys. Plasmas 14, 056309, 2007] on pre-refurbishment Z established a world record for laboratory fusion neutron yield. New experiments would establish ZR gas puff capability for x-ray and neutron production and could surpass previous yields. We present validation of ALEGRA simulations against previous Z experiments including X-ray and neutron yield, modeling of gas puff implosion dynamics for new gas puff nozzle designs, and predictions of X-ray and neutron yields for the proposed gas puff experiments.
High fidelity equation of state for xenon
Abstract not provided.
Neutron production in deuterium gas-puff implosions on the refurbished Z accelerator
It has been experimentally demonstrated that deuterium gas-puff implosions at >15 MA are powerful sources of fusion neutrons. Analysis of these experiments indicates that a substantial fraction of the obtained DD fusion neutron yields {approx} 3 x 10{sup 13}, about 50%, might have been of thermonuclear origin. The goal of our study is to estimate the scaling of the thermonuclear neutron yield from deuterium gas-puff implosions with higher load currents available after the refurbishment of Z, both in the short-pulse ({approx}100 ns) and in the long-pulse ({approx}300 ns) implosion regimes. We report extensive ID and 2D radiation-hydrodynamic simulations of such implosions. The mechanisms of ion heating to the fusion temperatures of 7-10 keV are essentially the same as used in structured gas-puff loads to generate high Ar K-shell yields: shock thermalization of the implosion kinetic energy and subsequent adiabatic heating of the on-axis plasma. We investigate the role of high-atomic-number gas that can be added to the outer shell to improve both energy coupling of the imploded mass to the generator and energy transfer to the inner part of the load, due to radiative losses that make the outer shell thin. We analyze the effect of imposed axial magnetic field {approx}30-100 kG, which can contribute both to stabilization of the implosion and to Joule heating of the imploded plasma. Our estimates indicate that thermonuclear DD neutron yields approaching 10 are within the reach on refurbished Z.
PIC/MHD modeling of dense plasma focus in 2D and 3D
Abstract not provided.
Strongly coupled plasma dynamics using the particle-in-cell methodology
Abstract not provided.
Possibility of using a Z pinch to investigate ion-electron equilibration
Abstract not provided.
ALEGRA-HEDP simulations of the dense plasma focus
We have carried out 2D simulations of three dense plasma focus (DPF) devices using the ALEGRA-HEDP code and validated the results against experiments. The three devices included two Mather-type machines described by Bernard et. al. and the Tallboy device currently in operation at NSTec in North Las Vegas. We present simulation results and compare to detailed plasma measurements for one Bernard device and to current and neutron yields for all three. We also describe a new ALEGRA capability to import data from particle-in-cell calculations of initial gas breakdown, which will allow the first ever simulations of DPF operation from the beginning of the voltage discharge to the pinch phase for arbitrary operating conditions and without assumptions about the early sheath structure. The next step in understanding DPF pinch physics must be three-dimensional modeling of conditions going into the pinch, and we have just launched our first 3D simulation of the best-diagnosed Bernard device.
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