Recent Advance in Isentropic Compression Experiments on PTS Facility.

The Primary Test Stand (PTS) facility is a pulsed power machine capable of delivering currents to loads with 5~8 MA over times of 200-620 ns. As current flows into the opposite direction electrode plates, smoothly rising, time dependent magnetic pressures are generated on each electrode plates. With pulse shaping techniques, the ramped compression waves can propagate in electrodes and specimens without shock formation. Photonic Doppler velocimetry (PDV) have been applied in shockless, free-surface or sample/window interface velocity measurements of different thickness samples, which were used for equation-of-state (EOS) studies of condensed matter. Analysis of the velocity data with Lagrange analysis, backward integration, and flow strength estimation techniques, the quasi-isentrope to ~100 GPa of OFHC copper and flow strength of tantalum under ~81 GPa isentropic compression were inferred. [ABSTRACT FROM AUTHOR]