Pb temperature determination using L-edge Extended X-ray Absorption Fine Structure

The temperature of dynamically compressed materials is the largest uncertainty in modern equation of state modeling, and developing new tools to measure temperature is important to complement data from existing diffraction and equation-of-state platforms. In experiments performed at the National Ignition Facility (NIF), we measured L-edge extended x-ray absorption fine structure (EXAFS) of dynamically-compressed Pb up to 300 GPa. These modulations in the x-ray absorption are caused by photoelectron scattering off nearby atoms, and are sensitive to both local atomic spacing and thermal disorder. The measured EXAFS are interpreted using density functional theory (DFT) and molecular dynamics (MD) simulations and compared agonist temperature determined using diffraction data in a different platform.