Equation of state and optical properties of warm dense helium

Abstract

We used molecular dynamics simulations based on density functional theory to study the thermophysical properties of warm dense helium. The influence of different exchange-correlation (XC) functionals was analyzed. We calculated the equation of state at high pressures up to several Mbar and temperatures up to 100 000 K in order to reconstruct recent static, single shock, and quasi-isentropic compression experiments. Furthermore, we calculated the dynamic electrical conductivity and determined the reflectivity and DC conductivity. We compared our results with experimental data and found good agreement between our calculations and the high-pressure experiments. The different XC functionals give similar results in the equation of state calculations, but have a strong impact on the reflectivity and the DC conductivity.