微空心阴极放电的流体模型模拟

采用流体模型研究了微空心阴极放电(MHCD)的特点，对放电中电场的形成，电子和离子的密度分布，电子能量分布进行了数值模拟.该计算是针对高气压，圆筒形阴极结构下的He放电.结果表明放电中存在空心阴极效应，从电子能量分布可以看出，放电中存在高能电子，放电空间的电场分布主要表现为径向电场.此外，通过改变气压，阴极孔径等参数计算出它们对放电的影响.分析表明减小孔径有利于负辉区更充分的重合.提高气压将缩短阴极位降区.关键词：微空心阴极放电流体模型

A fluid model for the simulation of discharges in microhollow cathode

A microhollow cathode discharge (MHCD) was investigated by means of a fluid model. A high-pressure He gas discharge for a cylindrical cathode was used in the model. The distribution of the electric field, electrons, ions and electron energy has been calculated. The results show that there exists a hollow cathode discharge effect in the discharge process. There existed electrons with high energy, and the electric field was mainly a radial field close to the cathode in the discharge area. The influences of gas pressure and dimension of the cathode on discharge characteristics were also investigated. We found that reducing the dimension of the cathode can enhance the hollow cathode effect, and increasing pressure will shorten the cathode fall.