Influence of Electric Field at Cathode Triple Junction on Flashover Characterestics in Vacuum

Abstract

Analytical and experimental investigations have been carried out to clarify the characteristic and the mechanizm of surface flashover in vacuum. Various insulator profiles made of PMMA having a certain contact angle with the cathode have been investigated. The simulation of surface charging based upon a secondary electron emission process is performed, which analyzes the electric field strength near the cathode triple junction considering the surface charge. It has been shown the flashover voltage of spacers experimentally obtained significantly depends on the electric field strength near the triple junction at the cathode.