为进一步揭示槽型空心阴极放电的放电机理,利用流体-亚稳态原子传输模型模拟研究了槽型空心阴极放电等离子体参数的时空分布特性。模拟得到了不同时刻槽型空心阴极放电中电势、电子密度、电场场强和电离速率等的分布特性。结果表明槽型空心阴极放电在不同时刻处于不同的放电模式,即初始放电阶段为Townsend放电模式,此阶段以轴向放电为主;第2阶段为放电由槽外向槽内发展阶段,此阶段电场场强由轴向向径向转换;第3阶段为形成空心阴极效应放电模式阶段,此阶段逐渐形成稳定的阴极鞘层结构;第4阶段为稳定放电阶段,放电参数不随时间发生变化。研究结果为进一步分析空心阴极放电的时间发展特性提供了参考。
In order to further explore the mechanism of discharge in slotted hollow cathode, we used a fluid-metastable atomic transport model to calculate the temporal and spatial plasma parameters of the discharge. Through the simulative calculation, we obtained the distributive characteristics of electric potential, electron density, electric field, and ionization rate varying with time. The results show that slotted hollow cathode discharge acts in different modes at different moments: The first stage is in the Townsend discharge mode, and it is mainly axial discharge. At the second stage, the discharge propagates from the outside to the inside of the cavity, along with a transition of electric field from axial to radial. The third stage is formation of hollow cathode discharge mode, and the cathode sheath layer is formed gradually at this stage. The last stage is stable discharge stage, the plasma parameters become time-independent. These conclusions provide a foundation for further analyzing the temporal characteristics of hollow cathode discharges.