偏压对射频空心阴极放电特性影响的PIC/MCC模拟研究

采用粒子网格(PIC)法与Monte Carlo碰撞(MCC)模型相结合的方法(PIC/MCC法),研究了在射频空心阴极放电系统中,负直流偏压(-10~-50 V)对放电特性的影响。通过模拟获得了在不同的外加负直流偏压下,空心电极孔内的电子密度、径向电场、轴向电场等参数的变化。计算结果表明,随着偏压从-10增加到-50 V,阴极孔内电子密度和径向、轴向电场逐渐增大;加偏压的孔内电子密度和径向、轴向电场比不加偏压的更大。从放电早期到达到稳定放电的过程中,电子逐渐从接地阳极附近移入空心电极孔内,孔内电子密度和径向、轴向电场随时间增长而增大;在同一时刻,放电系统施加偏压的孔内电子密度和径向、轴向电场比不加偏压的更大。达到稳定放电后,孔内电子密度和径向、轴向电场等不再发生变化。

Effect of Bias Voltage on RF Hollow Cathode Discharge: A Simulation Study

The RF hollow cathode discharge was mathematically formulated with 2-D particle-in-cell/Monte Carlo collision (PIC-MCC) model and numerically simulated with PIC/MCC software. The influence of the biasvoltage, on the discharge properties, including the electron peak density and electric field profile in the hollow cathode, was investigated. The simulated results show that the bias voltage has a major impact. To be specific, as the bias voltage increases from -10 into -50 V, the peak electron density, radial-and axial-field distributions, much large than those without bias voltage, significantly increase. In approaching to steady discharge state, the increasing bias voltage strongly drives electrons from the vicinity of grounded anode into the hollow electrode hole, resulting in considerable enhancement of the highly stable peak electron density and e-field profile.