同轴场畸变气体开关运行特性

Operational characteristics of gas switch with coaxial cylindrical electrodes and distortion field

开关静态工作特性通常会随放电次数的增加而发生某些变化。针对“强光一号”加速器工作初期、工作中后期和不稳定工作期的120只气体开关,在随机抽样的基础上进行静态实验,给出了三个不同阶段直流自击穿电压与气压的关系。根据0.08MPa下工作中、后期开关连续80次的直流自放电电压,同时利用Gauss和Weibull概率统计模型,分别计算了不同电压下单只开关和系统的自放电概率。结果均表明,对于工作中、后期的开关,当气压为0.19MPa时,在42kV运行电压下,加速器上120只气体开关不发生自放电的概率大于90%,与实际运行情况相符,此时开关的动态放电时延为170ns,抖动小于20ns。

In practice, the working properties of the 120 gas switches, which play an important role in the operation of LTD on Qiangguang I accelerator, vary with the number of discharges. With the accumulated shots of accelerator, the gas switches in LTD roughly pass through three different phases: initial phase, middle and post phase and erratic phase. The static characteristics acquired by experiments show that the switch in erratic phase with over 300 shots has discharging jitter about 20 to 33 percent. For the switch in middle and post phase with more than 100 shots, by analyzing the constant voltage data of static discharging of the switch of 0.08 MPa, the self-discharging probability is respectively presented with Gauss and Weibull distribution model; Further more, for 42 kV operation voltage of all 120 switches in LTD and the gas pressure of 0.19 MPa, the probability of no misfire incidents is not less than 90%, and the corresponding dynamic discharging delay and jitter time of the switch is about 170 ns and 20 ns, respectively.