Inhibited Transport in Dense, Partially-Ionized Plasmas

Transport processes such as diffusion, viscosity and conduction are important to quantify accurately in the hydrodynamic description of plasmas. In such models, these processes are typically captured through transport coefficients that relate the flux of one quantity in terms of the gradient in another. These coefficients encode plasma interactions at the microscopic scale, and thus require a detailed description of properties, such as the ionization state. For simplicity, plasmas are often described by assuming that every ion of a given species has a charge determined by the mean ionization state ("Z bar"). In reality, a partially ionized material will have a distribution of ionization states, but resolving this distribution can be quite challenging or even impossible for many theoretical descriptions. Here, we explore the effects of the variance in the ionization distribution on the theoretical predictions of transport physics. The general trend we find is the systematic reduction in transport rates when a finite variance in charge states is present, and we make connections to broader systems of plasma mixtures.