MC-PIC Simulation for Surface Discharge Inception Phenomena by Electrificated Charge

Abstract

We have studied the surface discharge initiation phenomena caused by attached charge itself. By using negative corona discharge, negative charge is attached to a film surface which covered a plane electrode in case of electrostatic probe method and to a BSO crystal surface in case of the Pockels effect. By lowering pressure, a ring-shaped discharge momentarily appears around the center of the attached negative charge. The relationship between the maximum tangential electric field strength and the critical pressure in the range of about 50 to 1000 hPa is obtained. It should be emphasized that the inception electric field is 6 to 8 kV/mm at atmospheric pressure and 0.5 kV/mm at 50 hPa. To clarify the mechanism of the surface discharge inception phenomena by electrificated charge, MC-PIC (Monte-Carlo Particle-in-Cell) simulation model, considering the gas photoinonization effect and the photoelectric effect on the electrified dielectric surface, is introduced. It was found that the photon produced in the active region plays an important role and especially the photoelectric emission from the electrified dielectric surface becomes the necessary condition for the surface discharge occurring.