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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 (LD 2) to examine its high-pressure equation of state (EOS). Using an impedance matching method, Hugoniot measurements were obtained in the pressure range of 30-70 GPa. The results of these experiments disagree with previously reported Hugoniot measurements of LD 2 in the pressure range above ~40 GPa, but are in good agreement with first principles, ab-initio models for hydrogen and its isotopes.

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A novel approach was developed to probe density compression of liquid deuterium (L-D2) 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. This technique has proven to be more sensitive than the conventional method of inferring density from the shock and mass velocity, at least in this high-pressure regime. Results in the range of 22-75 GPa indicate an approximately fourfold density compression, and provide data to differentiate between proposed theories for hydrogen and its isotopes.

We describe the injtial experiments to study the Z-pinch-drjven hohlraum ligh-yield jnertjal confinement fusion (ICF) concept of Hammer and Porter [J. H. Hammer et al., Phys. Plasmas, 6, 2129]. We show that the relationship between measured pinch power, hohlraum temperature, and secondary hohlraum coupling ("hohlraurn energetic") is well understood from O-D semi-analytic, 2-D viewfactor, and 2-D radiation magneto-hydrodynamics models. These experiments have shown the highest x-ray powers coupled to any Z-pjnch driven secondary (2655 TW), indicating the concept could scale to fusion yields of 400 MJ. We have also developed a novel, single-sided power feed, double-pinch driven secondary that meets the pinch simultaneity requirements for polar radiation symmetry. This source wjll perrnjt investigation of the pinch power balance and hohh-aum geometry requirements for ICF reIevant secondary radiation symmetry, leading to a capsule implosion capability on the Z accelerator [R. B.Spielman. er al.. Phys. Plasmas. 5,2105Plasmas. 5, (1998].

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Current equation of state (EOS) models for xenon show substantial differences in the Hugoniot above 100 GPa, prompting the need for an improved understanding of xenon's behavior at extreme conditions. We performed shock compression experiments on liquid xenon to determine the Hugoniot up to 840 GPa, using these results to validate density functional theory (DFT) simulations. Despite the nearly fivefold compression, we find that the limiting Thomas-Fermi theory, exact in the high density limit, does not accurately describe the system. Combining the experimental data and DFT calculations, we developed a free-energy-based, multiphase EOS capable of describing xenon over a wide range of pressures and temperatures.

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