X-ray spectroscopy of warm and hot dense matter

Optical lasers and x-ray lasers, such as the LCLS, can heat materials to extremely high temperatures, 10^4 – 10^6 K. These studies can simulate astrophysical conditions at an x-ray beamline. X-ray spectroscopy can provide quantitative information about the electronic structure of this matter. For warm dense copper, x-ray absorption spectroscopy has used to determine the electron temperature and to probe the electronic density of states. For a solid density aluminum plasma, x-ray emission spectroscopy has provided information on the ionization states, ionization energies and opacity.