Streamer-surface interaction in an atmospheric pressure dielectric barrier discharge in argon

Abstract

An atmospheric-pressure dielectric barrier discharge (DBD) in argon is investigated using a time-dependent and spatially two-dimensional fluid-Poisson model in axisymmetric geometry. The focus is on the streamer-surface interaction and the cathode-layer formation during the first discharge event in the single-filament DBD driven by sinusoidal voltage. A characteristic structure consisting of a volume streamer propagating just above the dielectric and simultaneous development of an additional surface discharge near the cathode is observed. The analysis of the electric field, electron production and loss rates, and surface charge density distribution shows that the radial deflection of the volume streamer is driven by free electrons remaining in the volume from the Townsend pre-phase and guided by the radial component of the electric field. The surface discharge occurring between the deflected volume streamer, which acts as virtual anode, and the dielectric surface is governed by ion-induced secondary electron emission and the surface charges accumulated on the dielectric.