介绍了具有预脉冲屏蔽板的水介质脉冲形成开关的结构和等效电路模型,给出模型中等效参数的计算方法.使用Pspice软件对该模型进行了电路模拟,着重分析预脉冲屏蔽板结构对输入、输出脉冲的影响,同时分析了开关电感和电极间隙电容对电压波形的作用.模拟结果表明,开关输入、输出端的对地电容对电压波形影响很大,开关电感和电极间隙电容的影响相对较小.对比"闪光二号"加速器上进行的水介质自击穿开关实验波形和模拟波形,说明在一定范围内等效模型是可以采用的.设计开关结构时,应先合理调整屏蔽板的位置以确定其对地电容,尽量兼顾减小开关电容和电感,屏蔽板开孔大小需选取适当.

The configuration and simulation model of water pulse forming line switch with prepulse suppression ground plane (PPS) were introduced in this paper. The influence of the PPS was analyzed using Pspice. As well as the capacitances between the electrodes or input/output line and PPS(C_pi and C_po), the inductance(L_p) and capacitance(C_p) of the gaps suppresses the prepulse. The simulation results indicate that the influence of the latter is small. The wave-shapes of the experiment on Flash-Ⅱ accelerator are compared with that of simulation. It suggests that the equivalent circuit model is feasible in water switch design. C_pi and C_po of the switch must make certain by adjusting the position of PPS firstly, L_p and C_p of the switch should be as small as possible, and the size of holes on PPS must be suitable.