Surface Flashover of Dielectrics During Low-Energy Electron Beam Irradiation in Vacuum

This paper deals with the surface flashover characteristics of dielectrics during low-energy electron beam irradiation in vacuum, considering large and high-power space systems to be constructed in low earth orbit in future and/or charged-particle beam apparatuses such as cathode ray tube (CRT). The flashover voltage was measured as functions of the dielectric distance and the time of voltage application. As results, the flashover voltage during electron irradiation was lower than that without electron irradiation, especially in case of longer dielectric distance. In V-t characteristic during electron irradiation, n value in Vf∝ T-1/n (Vf: flashover voltage, T: time to breakdown) was about 23. Methods to improve the flashover characteristic were also investigated.