Numerical simulation of dielectric-barrier-controlled glow discharge at atmospheric pressure

The space and time distributions of the electric field and the electron and ion densities, as well as the time evolutions of the discharge current density and the surface charge density of the dielectric layer in He dielectric-barrier-controlled glow discharge at atmospheric pressure are calculated by solving the one-dimensional continuity and momentum equations for electrons and ions, coupled to the current continuity equation. The properties of uniform atmospheric pressure glow discharge under the conditions of different driving frequency, voltage or dielectric layer are discussed and analyzed. When the driving frequency is high enough, a large number of ions are trapped and the induced space charge field makes a great many of electrons stay in the discharge volume. These seed electrons lead to a Townsend discharge at atmosphere pressure. The structure of this discharge is similar to that of low-pressure glow discharge, i.e. there exist four specific regions: the cathode fall, the negative glow, the Faraday dark space and the positive column. The discharge current becomes small with decreasing voltage amplitude applied. The secondary electron emission from the dielectric layer makes the discharge current increase. The thicker the dielectric layer is or the smaller the permittivity, the smaller the discharge current is.