Molecular Dynamics Simulations of Temperature Equilibration in Dense Hydrogen

TL;DR

This study uses molecular dynamics simulations to accurately determine temperature equilibration rates in dense hydrogen across various temperatures and densities, validating several theoretical models against simulation data.

Contribution

It provides a comprehensive validation of existing theoretical models for temperature equilibration in dense hydrogen using detailed molecular dynamics simulations.

Findings

GMS model agrees with simulations for Coulomb logarithms >1

Brown-Preston-Singleton approach aligns with data for all Coulomb logarithms

Landau-Spitzer models are valid for Coulomb logarithms >4

Abstract

The temperature equilibration rate in dense hydrogen (for both T_{i}>T_{e} and T_i<T_e) has been calculated with molecular dynamics simulations for temperatures between 10 and 600 eV and densities between 10^{20}/cc to 10^{24}/cc. Careful attention has been devoted to convergence of the simulations, including the role of semiclassical potentials. We find that for Coulomb logarithms L>1, a model by Gericke-Murillo-Schlanges (GMS) [Gericke et al., PRE 65, 036418 (2002)] based on a T-matrix method and the approach by Brown-Preston-Singleton [Brown et al., Phys. Rep. 410, 237 (2005)] agrees with the simulation data to within the error bars of the simulation. For smaller Coulomb logarithms, the GMS model is consistent with the simulation results. Landau-Spitzer models are consistent with the simulation data for L>4.