强流束二极管绝缘子结构设计与实验研究

Structure design and experimental study of intense beam diode insulator

介绍了一种应用于强流束二极管的径向绝缘结构,并对其在纳秒脉冲条件下的沿面闪络放电现象进行了研究。使用计算机模拟静电场的方法,对锥形结构绝缘子表面的电场分布进行了研究,优化了几何结构参数。在脉宽为40 ns,重复频率100 Hz的脉冲功率源上对绝缘子进行了实验研究。在历时18个月及100 000次脉冲实验后,发现绝缘子表面具有明显的树枝状放电现象,树枝状放电的根部碳化严重,绝缘子深度方向被完全击穿碳化,出现孔洞。基于固-液交界面闪络特性,对树枝状放电的可能原因进行了探讨。

A radial insulation structure used in an intense beam diode was introduced and the surface flashover across the oilsolid interface was studied. The geometry structure parameters were optimized by simulating the static electric field intensity distribution on the surface of the cone-shaped insulator. The experiment was done on a pulse power source with 40 ns pulse width and 100 Hz repetitive frequency. A bush-like streamer was observed on the insulator surface after 100 000 shots loaded in 18 months. The streamer root region of the insulator was severely carbonized and the breakdown and carbonization happened in the depth direction of the insulator, leading to the formation of pores. Based on the solid-liquid interface flashover mechanics, possible causes of flashover were discussed.