Dissociation and ionization equilibria of deuterium fluid over a wide range of temperatures and densities

TL;DR

This paper models deuterium fluid's dissociation and ionization over various temperatures and densities, incorporating high-density effects and a new free energy approach for more accurate predictions.

Contribution

It introduces a novel chemical model that accounts for high-density effects, partial electron degeneracy, and Coulomb interactions, improving upon previous models.

Findings

Enhanced agreement with experimental data

More accurate predictions of ionization and dissociation

Comprehensive isotherm datasets for deuterium fluid

Abstract

We investigate the dissociation and ionization equilibria of deuterium fluid over a wide range of temperatures and densities. The partition functions for molecular and atomic species are evaluated, in a statistical-mechanically consistent way, implementing recent developments in the literature and taking high-density effects into account. A new chemical model (free energy function) is introduced in which the fluid is considered as a mixture of diatomic molecules, atoms, ions and free electrons. Intensive short range hard core repulsion is taken into account together with partial degeneracy of free electrons and Coulomb interactions among charged particles. Samples of computational results are presented as a set of isotherms for the degree of ionization, dissociated fraction of molecules, pressure, and specific internal energy for a wide range of densities and temperatures. Predictions from the present model calculations show an improved and sensible physical behavior compared to other results in the literature.