Density Dependent Metallization and Plasma Phase Transition in Warm Dense Matter

Reflectivity saturation of shock compressed matter has been observed in a wide variety of materials, including hydrogen, helium, ammonia, hydrocarbons, and terrestrial minerals. This is often attributed to metallization. We present new double shock data for liquid deuterium and describe the degeneracy lifting, i.e., the quantum (liquid metallic) to classical (plasma) transition, at densities twice that of previous work. Moreover, by comparing these double shock data for deuterium with reflectivity data from a broad array of materials, we look towards a generalized description of the density and material dependence of reflectivity at the onset of metallization in the warm dense matter regime. This work is supported by the Department of Energy [National Nuclear Security Administration] University of Rochester "National Inertial Confinement Fusion Program" under Award Number DE-NA0004144, the Center for Matter at Atomic Pressures (CMAP), supported by the National Science Foundation under Grant No. PHY-2020249, and the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, and Quantum Information Science program under Award No. DE-SC-0020340.