title: Bayesian inference of x-ray diffraction spectra from warm dense matter with the one-component-plasma model.
abstract: We show that the Bayesian inference of recently measured x-ray diffraction spectra from laser-shocked aluminum [L. B. Fletcher et al., Nat. Photon. 9, 274 (2015)10.1038/nphoton.2015.41] with the one-component-plasma (OCP) model performs remarkably well at estimating the ionic density and temperature. This statistical approach requires many evaluations of the OCP static structure factor, which were done using a recently derived analytic fit. The atomic form factor is approximated by an exponential function in the diffraction window of the first peak. The electronic temperature is then estimated from a comparison of this approximated form factor with the electronic structure of an average atom model. Out-of-equilibrium states, with electrons hotter than ions, are diagnosed for the spectra obtained early after the pump, whereas at a late time delay the plasma is at thermal equilibrium. Apart from the present findings, this OCP-based modeling of warm dense matter has an important role to play in the interpretation of x-ray Thomson scattering measurements currently performed at large laser facilities.
authors.affiliation: CEA, DAM, DIF, 91297 Arpajon, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Clérouin
authors.affiliation: CEA, DAM, DIF, 91297 Arpajon, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Desbiens
authors.affiliation: CEA, DAM, DIF, 91297 Arpajon, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Dubois
authors.affiliation: CEA, DAM, DIF, 91297 Arpajon, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Arnault