Corrections to linear mixing in binary ionic mixtures and plasma screening at zero separation

TL;DR

This paper uses Monte Carlo simulations to refine the understanding of plasma screening and mixing corrections in strongly coupled binary ionic mixtures, with implications for nuclear burning in stellar environments.

Contribution

It introduces two methods to estimate plasma screening functions in ionic mixtures and demonstrates their agreement, improving models of plasma behavior in dense stellar matter.

Findings

Good agreement between two estimation methods for H_{jk}(0)

Corrections to linear mixing rule are characterized in strongly coupled mixtures

Implications for nuclear burning rates in dense stellar environments

Abstract

Using the results of extensive Monte Carlo simulations we discuss corrections to the linear mixing rule in strongly coupled binary ionic mixtures. We analyze the plasma screening function at zero separation, H_{jk}(0), for two ions (of types j=1,2 and k=1,2) in a strongly coupled binary mixture. The function H_{jk}(0) is estimated by two methods: (1) from the difference of Helmholtz Coulomb free energies at large and zero separations; (2) by fitting the Widom expansion of H_{jk}(x) in powers of interionic distance x to Monte Carlo data on the radial pair distribution function g_{jk}(x). These methods are shown to be in good agreement. For illustration, we analyze the plasma screening enhancement of nuclear burning rates in dense stellar matter.