On-line measurement of pulsed electric-field of insulator surface in vacuum based on Kerr effect

In this work, an on-line measurement system based on Kerr effect is established to investigate the surface electric field of insulator stressed by HV pulse in vacuum. A basic measurement principle based on Kerr effect is narrated. According to this principle, a linear optical polarization configuration is arranged in measurement system. An 180kV Marx generator, high-voltage cable as pulse forming line are utilized to output a square nanosecond HV pulse stressing on insulator specimen in Kerr cell, once a gas switch is conducted by a laser pulse emitted from a YAG laser. And a synchronous controlling apparatus is developed to make sure that the measurement on surface electric field is performed during the HV pulse being stressed on insulator. Accordingly, a preliminary experimental observation on surface electric field at onset of flashover is performed.