Collisional stopping power of ions in warm dense matter

TL;DR

This paper introduces a plasma kinetic model for ion stopping power in warm dense matter, incorporating quantum effects and strong correlations, achieving comparable accuracy to density functional theory at lower computational cost.

Contribution

It develops a novel kinetic model that accounts for Fermi degeneracy and Coulomb correlations in warm dense matter, improving prediction accuracy and computational efficiency.

Findings

Model matches density functional theory results for deuterium near solid density

Captures transition from classical to degenerate plasma behavior

Provides a computationally efficient alternative to DFT calculations

Abstract

A model for the collisional stopping of ions on free electrons in warm dense matter is developed and explored. It is based on plasma kinetic theory, but with modifications to address the warm dense matter regime. Specifically, it uses the Boltzmann-Uehling-Uhlenbeck kinetic equation to incorporate effects of Fermi degeneracy of electrons. The cross section is computed from quantum scattering of electrons and ions occuring via the potential of mean force derived from an average atom model, which incorporates effects of strong Coulomb correlations. Predictions from this model show comparable accuracy to results from time-dependent density functional theory calculations for deuterium near solid density and a temperature of several electronvolts, at a fraction of the computational cost. Further, the model captures the transition of a plasma from the classical limit to the degenerate limit, including qualitative behaviors of solid state theory.