Update on multi-megabar shockless compression at Sandia’s Z machine (2020)*

Quasi-isentropic, shockless ramp-wave experiments promise accurate equation-of-state (EOS) data of materials in the solid phase at relatively low temperatures and multi-megabar (100’s GPa) pressures. In this range of pressure, isothermal diamond-anvil techniques have limited pressure accuracy due to reliance on theoretical EOS of calibration standards, thus accurate quasi-isentropic compression data would help immensely in constraining EOS models. Multi-megabar shockless compression experiments using the Z Machine at Sandia as a magnetic drive with stripline targets have been performed on many solid materials over the past decade. An update is given on recent results and developments, including experimental techniques, analysis methods, and uncertainty quantification.