Diffusion in Molecular Dynamics Simulations of Strongly Coupled Plasma Mixtures

Diffusion coefficients in plasmas are an essential piece of microphysics for studying stellar interiors, inertial confinement fusion, and more. However, diffusion coefficients are not trivial to solve for. Large simulations must be done over several orders of magnitude in temperatures to get accurate diffusion coefficients to fit models for diffusion in mixtures. In this work, we report on molecular dynamic simulations of two component plasmas with a screened Coulomb force using a range of screening lengths relevant to astrophysics. We find a strong dependence on the charge ratio of the mixture with a weaker dependence on the screening length, except at strong coupling. We develop a scaling law to describe the relationship.