Off-Hugoniot mechanical response of metal standards at the Z machine

Static and dynamic compression experiments have historically used simple metals as standards; examples include Au and Pt in diamond-anvil cell work, Al and Cu electrodes in magnetically-driven experiments, and, more recently, Pt and Ir pushers in shock-ramp experiments at Sandia’s Z machine. These materials’ mechanical equations of state at low temperature have traditionally been deduced from shock Hugoniot measurements, a procedure that has limited accuracy at pressures > 100 GPa due to shock melting. To validate existing models, and stimulate the creation of new models, we have begun a systematic study at the Z machine of metal standards under far off-Hugoniot dynamic compression loading using shockless and shock-ramp techniques to peak stresses > 300 GPa, including measurements of strength under release from shocklessly-compressed states. After a brief introduction to the experimental approach, results and comparison to models will be presented for two or more metals.