Classical theory of the pair distribution function of plasmas

Abstract

The diagrammatic method used by Abe to obtain the Helmholtz free energy of the classical electron gas is used to derive the pair distribution function beyond the Debye-Hückel result. The calculation can be done systematically either in configuration space or wave-number space and is carried out exactly to O(Λ2) where Λ=14πρλD3 is the classical plasma parameter. It is shown that g(r) has the form g(r)=e-βus[1+g2b(r)+g2c(r)], where us=(e2r)exp(-rλD) is the Debye screened potential, and g2b and g2c are functions of rλD which are evaluated analytically to O(Λ2). For the region βe2