Monatomic plasma-thermal radiation interaction: a weakly-ionized kinetic model

Abstract
A model for the kinetic formulation of a weakly-ionized monatomic gas, which interacts with thermal radiation, is proposed. The collision terms for particle-initiated ionization, developed in terms of a non-equilibrium degree of ionization, and the collision terms for photon-initiated ionization, developed by assuming particles remain in local equilibrium during photon relaxation, all satisfy the usual conservation principles. It is also shown that the proposed model leads to an H theorem.