Equation of State for Binary Ionic Plasmas, Fluid and Solid Phases

Abstract

This paper gives a summary of the most recent Monte Carlo simulation data for the internal energy, U/NkT, for the the One Component Plasma (OCP) and Binary Ionic Mixtures (HIM) for both fluid and solid phases. The Monte Carlo results are compared with Molecular Dynamics results of nearly the same accuracy. The OCP fluid and solid data are used to give the most accurate available equation of state for both the fluid and the crystalline (bcc) phases of the OCP. For the BIM mixture with 5% charge 2. and 95% charge 1. the deviations from linear mixing are given to the best available accuracy. These results make it possible to obtain the classical contribution to the screening enhancement of thermonuclear reaction rates for white dwarf stars. Current results on deviations from linear mixing are also given for random ionic mixtures for which the two different charges are placed randomly on bcc lattice sites. It is found that the deviation from linear mixing in the crystalline solid is roughly an order of magnitude larger than deviations from linear mixing for BIM fluids. The data supports the conclusion that the phase diagram for a BIM mixture is spindle shaped for carbon and oxygen mixtures found in white dwarf stars.