Compton Scattering and Warm Dense Matter Thermometry

Abstract

The purpose of this dissertation is to consider the level of detail required for proper theoretical description of non-resonant inelastic x-ray scattering (NIXS) experiments from warm dense matter (WDM). These experiments currently provide the primary means of diagnostic thermometry for low-Z elements of interest for inertial confinement fusion. In particular, I focus on the importance of non-perturbative ion-electron interactions and their effect on the NIXS spectrum. To this end, I have extended the real-space electronic structure code FEFF to both calculate the valence-electron contribution to the NIXS spectrum and to handle elevated electronic temperature. I have found that the ion-electron interaction, and in particular the constraint of orthogonalization between core and valence wavefunctions results in a significant broadening of the valence-electron NIXS spectrum. This effect, has a similar appearance as increasing both density and temperature in simpler models of the valence-electrons in WDM, and thus significantly affects the accuracy of thermodynamic parameters extracted from experimental data. Additionally, I have also demonstrated improved models for treating the core-shell contribution to the NIXS spectrum.