Investigation of laser-triggered water switch under 130 kV microsecond rise-time pulse

Experiments about the laser-triggered water switch under microsecond rise-time pulse were done. Relation between the jitter of trigger breakdown delay time and the length of laser-induced water breakdown arc, laser energy and trigger time was researched. A water gap was designed for these experiments. The gap has two electrodes, one is a hemispheroid and the other is a plate. A hole in the hemispheroid electrode is designed for the laser. From self-breakdown experiments results, self-breakdown voltage of the water switch is about 133 kV, and jitter of self-breakdown delay time is about 263 ns. The jitter of breakdown delay time was reduced to less than 30 ns by laser-triggering. The laser energy has little influence on the jitter of breakdown delay time when the energy is higher than 19 mJ in the experiments.