Online Measurement of Pulsed Electric Field of Insulator Surface in Vacuum Based on Kerr Effect

An online measurement system based on Kerr electro-optical effect is developed to investigate the surface electric field of insulator stressed by high-voltage (HV) pulse in vacuum. A basic principle of Kerr effect is narrated. According to this principle, a circular optical polarization configuration is arranged to detect the phase difference caused by Kerr effect. An 180-kV Marx generator and an HV cable serving as pulse-forming line are utilized to output an HV pulse stressing on insulator specimen in Kerr cell. In addition, a synchronous controlling apparatus is developed to make sure that an online measurement on surface electric field is performed during the HV pulse being stressed on the insulator. As a result, distortion of surface electric field of insulator is observed in experiments preliminarily.