X-ray near edge spectroscopy (XANES) as a probe of warm dense matter

Stephane Mazevet
Observatoire de Paris

X-ray near edge spectroscopy has become the method of choice to reveal the change taking place at the electronic structure level as materials are submitted to pressures up
to a few Mbars using diamond anvil cell (DAC). This technique provides unprecedented details on how materials transform under large pressure increases but has remained mostly used at the moderate temperatures accessible to the static DAC measurements. For dynamical experiments, where matter is brought into extreme conditions during less than a few picoseconds using, for example, z-pinch or high-power
lasers to name a few, the diagnostics in place have been mostly limited to VISAR (Velocity Interference ) measurements that access shock velocity, or transport properties such the reflectivity at a given wavelength. Using ab initio simulations, we investigate the usefulness of XANES measurements as a probe warm dense matter.

Back to Workshop IV: Computational Challenges in Warm Dense Matter