Plasma Thermal Conductivity with Collective Effects

Abstract

The electron thermal conductivity of a fully ionized Lorentz gas has been studied. The energy transfer among regions of the gas at different local temperatures has been determined by considering the emission and absorption of longitudinal plasma waves. These waves are both collision and Landau damped; the latter type of damping effects the energy transfer only secondarily, since the resulting energy does not go directly into the heating of the gas. The results obtained by assuming infinite Landau damping are expected to agree with typical two-body collision treatments. However a non-vanishing plasma parameter, which results in finite Landau damping, facilitates the introduction of a variety of collective effects. Thus, it is found that, beyond the dependences obtained in conventional two-body collision studies, the thermal conductivity exhibits an additional weak dependence on the plasma parameter.