Breakdown performance of water switches in Qiangguang-Ⅰ facility

The behaviors of three kinds of self-breakdown water switches for Qiangguang-Ⅰaccelerator were studied. They have different configurations including sphere-plane structure, local field-enhanced sphere-plane structure and annulus-plane structure. By computer simulation,the electric field parameters were determined. The breakdown characteristics of the switches were tested in Qiangguang-Ⅰfacility. Experimental results of three different kinds of switches show that the annulus-plane structured ha= s the switch stablest breakdown performance. The time jitter of the annulus-plane switch for 15 shots is only 30 ns, comparing the 60 ns and 140 ns of the local field-enhanced sphere-plane structure and the sphere-plane structure respectively.In addition to the standard electrical diagnostics, opt