Temperature measurements on shocked two-phase Ce

The ability to understand and predict the response of matter at extreme conditions requires knowledge of a materials equation-of-state (EOS) including the location of phase boundaries, transitions kinetics, and accurate measurements of temperature at pressure. Recent developments in optical pyrometry have provided methods for measuring temperature in the shocked state, and these have been used to study the phase diagram for some metals including cerium. Cerium has received significant attention because it exhibits a rich phase diagram that includes an anomalous melt boundary and a low-pressure shock-melt transition. In this work, we continue our study of shock-melting using optical pyrometry to measure the temperature and stress states for two-phase cerium (γ-Ce and β-Ce) shocked into the high-pressure liquid phase. These results will be compared to the previously measured results for single phase Ce (γ-Ce) with the goal of gaining further insight into the shock melt transition and associated kinetics. Details of the experimental methods, analysis, and results will be presented (LA-UR-21-30567).