Kinetic theory of electromagnetic instabilities in weakly ionized neon plasma with inelastic collisions

The spectra and the instability criteria for the two electromagnetic wave modes previously found to exist in weakly ionized plasmas placed in an external d.c. electric field are analysed here for neon plasma for a wide range of the parameter E_o/n_n. The presence of electron-atom inelastic collisions is taken into account, assuming that the electron temperature is in the range where these collisions dominantly result in atomic excitations. The linearized kinetic equations are used in combination with a previously evaluated non-Maxwellian electron steady-state distribution function appropriate for the situation in which collisional excitations are significant. For any given ratio of electron drift to thermal velocity, the wavelengths and the angles of propagation at which the instabilities are predicted to set in are determined.