高功率微波脉冲大气击穿概率研究

Probability distribution of high power microwave pulse breakdown in air

高功率微波大气击穿实验中,入射功率在大气击穿阈值附近,即使外界条件相同,大气击穿可能发生也可能不发生。针对这一问题,基于大气击穿机理,将大气击穿分为首个电子出现在击穿区域和高功率微波电场导致雪崩击穿两个过程。针对第一个过程,建立了改进的电子连续性方程,引入平均电子产生率分析大气击穿发生前电子出现的概率问题;针对第二个过程,建立了高功率微波大气雪崩击穿概率模型。综合两个过程,建立了高功率微波大气击穿概率模型,仿真了不同压强条件下大气击穿的概率,并与相关实验数据进行了比对,仿真结论与实验数据吻合较好。

In recent experiment about air breakdown induced by high power microwave,when the incident microwave value is set near the breakdown threshold,it can be found that although all the other external conditions are the same,it is not certain that the air breakdown will occur.To solve this problem,the mechanism of air breakdown was studied and we divided air breakdown into two stages,one stage was the appearance of the first free electron in the breakdown region,the other was the avalanche induced by microwave electric field accelerate electron.A novel model combining average electron generation rate model and avalanche breakdown model was proposed to simulate the probability distribution of high power microwave breakdown in air.The air breakdown probability distribution was simulated under conditions similar to the experiments,and the simulated results agreed well with the experiment data.