POLARIZABILITY OF PARTIALLY-IONIZED, DENSE-PLASMAS (APPLICATION TO PHOTOABSORPTION CALCULATIONS)

A theoretical approach to the polarizability of plasma electrons is presented. The formalism takes into account both bound and free electrons. The methods used are: density functional theory for electrons, random phase approximation for the response of the electron density and the cluster expansion in the average over the ion configurations. The first order of the cluster expansion leads to equations for the polarizability of the average atom. A perturbational approach to this polarizability is proposed. The theory may be applied to static polarizability which express the variances in the statistical broadening of the average atom. A numerical example for gold at 750 eV temperature and solid density is discussed.