Influence of the Transverse Field Component on the Edge Effect in a Short-Gap Discharge

Abstract

In a general plane-parallel electrode system, the edge of the electrode will undermine the uniformity of the dielectric barrier discharge (DBD) because of the influence of the distorted electrical field. In this paper, the influence of the non-uniform electrical field on the edge effect of DBDs in a short-gap is investigated. We present some of the experimental results of DBDs produced by three kinds of convex-spherical electrodes. The results show that there is a dark area (the homogeneous discharge) in the central region of the electrode and a bright halo (the filamentary discharge) in the outer peripheral region, and the radius of the dark region is determined by the electrode geometry. The calculated results of the transverse (radial) field component distribution on the surface of the electrodes show that the edge effect does not come from the electrode edge, but the transverse field. The discharge has enough space to be fully developed and then format the filamentary discharge in the outer peripheral region because the streamer of the filamentary discharge is driven to move along the direction of the longer path by the transverse field. Thus, the homogeneous discharge (the Townsend DBD or a glow DBD) could not be produced in this area.

Effects of the transverse electric field on nanosecond pulsed dielectric barrier discharge in atmospheric airflow

“…For the symmetric electrode geometry, on the one hand, the electric field at the electrode edge is stronger than that in the central region [17,22], which can generate more electron avalanches. On the other hand, it has been reported that there is a transverse electric field component at the electrode edge [12,23]. The spatial ions in the microdischarge channels at the electrode edge have a transverse movement under the effect of the transverse electric field, and drag the surface electrons through an electrostatic coupling force, which leads to the redistribution of the space charges.…”

“…But they did not provide an explanation for the role of the edge effect in pattern formation [13]. For the diffuse discharge at the electrode edge, less attention has been paid to the influence of the transverse electric field on discharge [12,23]. It has been reported in previous work that the transverse electric field at the electrode edge is responsible for the generation of diffuse discharge [12].…”