Effect of UV illumination on surface flashover characteristics of epoxy resin under pulse

Surface flashover in vacuum is a primary limitation to pulsed-power devices. Recently, there are more studies on the pulsed vacuum surface flashover focused on the flashover mechanism. In this paper, the UV illumination is used to study the mechanism of vacuum surface flashover. The effects of different illumination positions, different illumination durations and different illumination intensities are investigated. The results show that the pulsed vacuum surface flashover characteristic is affected by the UV illumination significantly. When the UV light illuminates the cathode triple-point junction, the flashover voltage is reduced; this reduction is almost unaffected by the illumination duration, but significantly increased with the enhancement of illumination intensity. When the UV light illuminates the sample surface, the flashover voltage reduction is increased both by the increases of illumination duration and illumination intensity. Moreover, UV illumination can also change the surface potential and thus influence the surface flashover characteristic.