微波击穿中压强对电子弛豫过程的影响

通过联立电子密度和电子能量随时间的演化方程构建全局模型,对不同压强下高功率微波(HPM)脉冲氩气击穿及电子弛豫过程进行了研究。计算了不同压强下的氩气击穿阈值,其与粒子模拟蒙特卡罗碰撞(PIC/MCC)法预测的结果符合得很好。通过引入复合率和扩散率的经验表达式,得到了不同压强下,弛豫过程中电子密度和电子能量随时间的变化。结果表明,氩气击穿发生后,电子密度先经历短暂的增长后逐渐下降,且压强越高,电子密度的最高值越低。在电子弛豫过程中,随着压强的增加,电子密度下降得更慢,而电子能量减小得越快。

Effects of pressure on the electron relaxation process in microwave airbreakdown

A global model, which consists of the electron density and electron energy evolution equations, is used to investigate the effects of pressure on the electron relaxation process in the argon breakdown by the high-power microwave (HPM) pulse. Numerical simulation shows that the breakdown time obtained by the model agrees well with the Particle-in-cell-Monte Carlo collision (PIC/MCC) prediction. Empirical formulas for Recombination rate and diffusion rate are introduced into the model, and the time evolutions for electron density and electron energy are simulated at different pressures. The results show that the electron density first increases at a short time and then decreases after the argon breakdown occurs, and the maximum value of the electron density decreases as the pressure increases. The electron relaxation time becomes longer at a higher pressure.