315 / 2023-05-04 10:39:50

Studies of the structure and x-ray Thomson scattering of warm dense matter - 侯永

高压物理与材料科学 > 动高压-II

    Warm dense matter (WDM) refers to conditions between the physical regimes of condensed matter and weakly coupled plasmas, with temperatures from a few to few hundred electron-volt (eV) and densities from a few hundredths to hundred times solid density. Understanding the precise physical properties of WDM, such as the equation of state, the radiation opacity and the transport properties, is crucial for modeling astrophysical objects and inertial confinement fusion (ICF) experiments. However, describing WDM faces great challenges since partial ionization, electron degeneracy, bound-state level shift, pressure ionization and ion-ion strong coupling must be taken into account in a consistent way. In particular, the accurate description of the coupled electron-ion system is of paramount important for WDM states.

    Spectrally resolved x-ray Thomson scattering (XRTS) experiments have shown that the plasma parameters of WDM such as temperature, density and average ionization degree can be determined. We have developed different theoretical models to describe the electronic and ionic structures of warm dense matter, self-consistently. When the electron structures are calculated, the other ionic and electronic influences are considered by the correlation functions by using the average-atom model. And the ionic correlation functions are obtained after obtaining the electronic structures. On basis of the electronic and ionic structures, dynamic structure factor is computed according to the Chihara formula, where the scattering contributions are divided into three components: ionic elastic part, bound-free, and free-free inelastic parts. As an example, the dynamic structure factor of CH mixture is presented.