在对神龙二号加速器绝缘环进行耐压考核时发现, 感应腔中的绝缘支撑部件交联聚苯乙烯绝缘环在猝发多脉冲高压加载下出现的真空沿面闪络现象存在两种类型: 阴极始发的闪络击穿和阳极始发的闪络击穿。通过计算绝缘环的沿面电场分布、对比击穿电压波形与绝缘环表面闪络放电烧蚀痕迹, 结合小绝缘子样品实验结果对以上沿面击穿现象的机理进行了分析, 认为可能是绝缘环端面与电极面的配合问题引起了加速段与注入器绝缘环击穿现象的差异。

Two types of flashover phenomenons were discovered during the high voltage test of Dragon-Ⅱ linear induction accelerator insulator ring, which was made by cross-linked polystyrene. One type of the flashover was initialized from cathode and the other one was initialized from anode. The mechanism of the phenomenon was analyzed by comparing breakdown voltage waveform and discharge trace, and calculating electric field combination with flashover experiment on little insulator samples. It is assumed that the cooperating problem of the insulator and cathode caused the difference between accelerator and injector insulator ring flashover.