Optical diagnostics of 2.4 MV annulus-flat water switch in Qiangguang-I facility

The optical diagnostics of annulus-flat water switch in “Qiangguang-Ⅰ” facility was carried out utilizing optical framing camera and fiber sensor. The images of the discharging channels and the irradiance intensity signal during charging stage were acquired. The experiment results showed that the average breakdown electric field of annulus-flat water switch was about 190 kV/cm, several discharging channels were observed at the same time, the streamers appeared like bush and their velocity was about tens of cm/μs.