Breakdown of a gas gap in a surface barrier discharge

The processes that occur in a surface barrier discharge in oxygen at atmospheric pressure have been studied by numerical modeling. Modeling is performed assuming the existence of local equilibrium, and the dynamics of charged particles in the gas gap is calculated using continuity equations. The configuration of the electric field in the discharge zone is determined by integration of the Poisson equation. It turns out that the breakdown of the gas gap is determined by the photoemission from the cathode surface. The appearance and development of the microdischarge channel are sustained by the cathode layer that is formed at the conducting cathode. The parameters of the cathode layer obtained in oxygen at atmospheric pressure are virtually the same as for the ordinary cathode layer of the glow discharge.