Quantum-statistical equation-of-state models of dense plasmas: high-pressure Hugoniot shock adiabats

TL;DR

This paper compares two quantum-statistical models for dense plasmas to predict high-pressure shock behaviors, highlighting the advantages of the atom-in-a-jellium approach in handling pressure ionization and shell effects.

Contribution

It introduces a comparative analysis of atom-in-a-spherical-cell and atom-in-a-jellium models for high-pressure equations of state, emphasizing the improved treatment of pressure ionization by the jellium model.

Findings

Both models accurately predict Hugoniot shock adiabats in the 1 Mbar-10 Gbar range.

The atom-in-a-jellium model better captures pressure ionization effects.

Shell effects influence pressure, shock velocity, and electronic specific heat variations.

Abstract

We present a detailed comparison of two self-consistent equation-of-state models which differ from their electronic contribution: the atom in a spherical cell and the atom in a jellium of charges. It is shown that both models are well suited for the calculation of Hugoniot shock adiabats in the high pressure range (1 Mbar-10 Gbar), and that the atom-in-a-jellium model provides a better treatment of pressure ionization. Comparisons with experimental data are also presented. Shell effects on shock adiabats are reviewed in the light of these models. They lead to additional features not only in the variations of pressure versus density, but also in the variations of shock velocity versus particle velocity. Moreover, such effects are found to be responsible for enhancement of the electronic specific heat.