The Boltzmann equation for the electron gas in a dielectric is constructed. Equations for the moments of the electron distribution function—concentration, drift velocity and energy density of the electron gas—are obtained. Closed equations for the electromagnetic field, concentration, and temperature of nonequilibrium electrons are derived in the drift approximation. Under the assumption that the electron gas is nondegenerate and the density of energy states of electrons is quasi-classical, the rate of the impact ionization reaction of the dielectric near the ionization threshold is calculated.
Volkov et al. (Wed,) studied this question.