Equation of state measurements in warm dense fluids on Z and OMEGA

Constraining material properties at extreme conditions is necessary to understand astrophysical processes and stellar structures. High-bandgap fluids present difficulty for first-principles molecular dynamics techniques such as density functional theory or quantum Monte Carlo calculations. Over the past decade, we have studied the equation of state for argon, neon, and oxygen in the warm dense matter regime using shock experiments on both the Z at Sandia National Laboratories and OMEGA laser at the University of Rochester Laboratory for Laser Energetics, as well as first-principles calculations. We present principal Hugoniot, reshock, and temperature measurements for liquid argon, neon, and oxygen in the warm dense matter regime. Good agreement between both experimental platforms is demonstrated for argon and neon and the results also agree well with theoretical calculations. Description of the oxygen fill station at OMEGA and initial experimental results for two initial densities are compared with theoretical calculations.