Quasistatic simulation of microwave discharges in a spherically symmetric electrode system in nitrogen

Results are presented from one-dimensional quasistatic simulations of steady microwave discharges in a spherically symmetric electrode system in nitrogen at pressures of 1–8 Torr. The computational model includes the equation for calculating the electric field strength in the quasistatic approximation, Poisson’s equation, the balance equations describing the kinetics of charged and neutral plasma particles, and the time-independent homogeneous Boltzmann equation for electrons. The processes involving vibrationally excited particles are taken into account by the familiar analytic expression for the vibrational distribution of molecules in the diffusion approximation. It is shown that, because of the electric field nonuniformity, the physical properties (in particular, the plasma ion composition) are different in different discharge regions.