Two-dimension simulation of small scale dielectric barrier discharge in argon

Low temperature plasma generated by dielectric barrier discharge (DBD) has been paid more and more attention in recent years for its wide range of potential applications. In this paper, atmospheric argon DBD is ignited in a small gas gap of 0.1mm between two parallel glass plates covered by circular copper electrodes with a radius of 0.7 mm. A two-dimension axisymmetric numeric model, coupled with fluid and Poisson equations, is built to clarify the discharge evolution. The basic process of discharge, mainly controlled by electron energy and electric field, is analyzed, which is divided into three stages including Townsend-like discharge, streamer development and discharge extinction. Through the simulation, the spatial-temporal distribution of electron, space charge, surface charge and electric field are investigated, which indicates that the space charge plays a key role in the development of discharge. When the DBD is driven by applied voltage, five discharge channels can be found at the end of the discharge current pulse. The electric field distorted by space charge is expected to be responsible for movement of ionization wave. The surface charge is believed to be the main factor affecting the distribution of five discharge channels.