Cathode-like luminescence on vacuum-dielectric interface under DC voltage based on self-stabilizing secondary electron emission

A particular Cathode-like luminescence (CLL) phenomenon occurring on vacuum-dielectric interface under high DC electrical field before or accompanied with flashover is reported, which is widely existed in vacuum-dielectric system. It is considered that the CLL presented in this paper is initialized by field electron emission at Cathode Triple Junction (CTJ) and finally generated by a process of radiative recombination due to the self-stabilizing secondary electron emission (SSEE) and collision on surface of insulator. The spectrum of CLL is measured and analyzed, and it shows that there are not any characteristic spectrums of C, O, N, which means that the CLL is not produced by discharge of desorption gas. In addition, simulation results also approved that the SSEE process in fact exists. Finally, its relevance to flashover is also discussed. It shows that flashover seldom occurs on the channels of CLL, which seems that the CLL has an inhibition effect on flashover. However, the exact mechanism is still unclear. This work will be researched in near future.