Generalized thermodynamic functions for electrons in a mixture of hard spheres: Application to partially ionized nonideal plasmas

Abstract

We present an ad hoc generalization of thermodynamic functions for electrons in a mixture of hard spheres which describes the reduced-volume effect at an arbitrary degree of degeneration. The model is applied to dense low-temperature plasmas in the region of partial ionization and, therefore, has to be supplemented by expressions for the Coulomb interaction between strongly coupled ions in an electronic background. A comparison with previous treatments of the reduced-volume effect shows the significant influence of our approach on the nature of the pressure ionization what is illustrated by numerical examples for a helium-like model plasma.