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Aluminum has been investigated at multi-Mbar pressures through planar impacts generated by guns and explosives, and ablatively driven shocks from high energy lasers. Because it is well characterized, it is often used as a reference in relative Hugoniot measurements. To determine equation of state measurement capabilities on the Sandia Z accelerator, Hugoniot states of type 1100 aluminum were determined in the 1.8 to 4.5 Mbar range for comparisons to published data. Ablatively driven shocks on 6.5mm diameter samples were measured using velocity interferometry and laser based shock arrival sensors. In each experiment, both shock and particle velocities were independently measured to determine Hugoniot states. Many of the experiments performed had multiple measurements of these two parameters for redundancy and diagnostic validation. Results indicate agreement with the extrapolation of a previously established, lower pressure, Hugoniot within error bounds representing the experimental uncertainties. [ABSTRACT FROM AUTHOR]

Recent NOVA laser experiments featuring ablatively-generated data on very small liquid deuterium samples have shown an unexpected degree of compressibility in deuterium as it undergoes molecular dissociation to a metallic phase above 25 GPa. To test these controversial results under somewhat different shock loading conditions, we have developed a cryogenic target system on the Sandia Z pulsed radiation source for precision EOS studies of liquid deuterium using radiation-driven shocks. Experiments are underway to develop a constant pressure drive of 10-20 ns duration spatially uniform over a relatively large area (3-4 mm diameter) with minimal preheat effects. Techniques are also being developed to perform fiber-optic-coupled VISAR interferometry, active shock breakout, and optical spectroscopy measurements on the stepped Al pusher plate and liquid deuterium sample in the Z bremsstrahlung environment. Initial VISAR measurements have been able to track the highly reflective metalized shock front propagating in deuterium at pressures of about 55 Gpa. [ABSTRACT FROM AUTHOR]

We are investigating direct laser-produced plasmas as an ion source for the PBFA II pulsed power accelerator. Laser-generated plasmas have several potential advantages for this application, including the ability to generate a pre-formed anode plasma, simplicity, and flexibility. Previous experiments have shown that a high-density lithium plasma can be produced by direct laser irradiation of a solid lithium surface with a pulsed dye laser tuned to the Li 1s-2p resonance line at 670.8 nm (Laser Ionization Based On Resonant Saturation - LIBORS). We are also investigating a two-step approach, which uses a short-pulse Nd:YAG laser to efficiently vaporize the lithium-bearing source material, followed by LIBORS ionization of the evolving vapor to produce plasmas of mid-1016/cm3 densities. [ABSTRACT FROM PUBLISHER]