一种陶瓷径向绝缘强流二极管耐压结构设计

 对外径230 mm的陶瓷绝缘板，依据强流真空二极管径向绝缘的设计思想，设计加工了“锥-柱”型阳极外壳，并在传输线内筒和阴极杆末端位置增加了均压罩和屏蔽环结构。利用静电场有限元程序计算了陶瓷-真空界面电场分布，通过对外壳细节结构以及均压罩、屏蔽环形状和位置的调整，使得真空界面上沿面场强和三结合点处场强均得到了有效控制。在单线长脉冲加速器上进行了实验研究，结果显示，二极管能够耐受400 kV、脉宽大于200 ns的脉冲电压，运行稳定，达到了理论设计要求。

Design of a ceramic radial insulation structure for a high current diode

For a high current diode composed of a small disk type ceramic insulator water/vacuum interface,the design of radial insulation structure is presented.According to the theory of vacuum flashover and the design rules for radial insulation,a "cone-column" anode outline and the cathode shielding rings were adopted.The electrostatic field along the insulator surface was obtained by FEA simulation.By adjusting the outline of the anode and the shielding rings,the electric fields were well distributed and the field around the triple junction was controlled.A high voltage test was carried out on a water isolated spiral pulse forming line(PFL) accelerator with 200 ns pulse width,and the results show the diode can work stably in 400 kV,200 ns conditions.