纳秒脉冲下高能量快电子逃逸过程的计算

Calculation on runaway process of high-energy fast electrons under nanosecond-pulse

基于快电子的逃逸击穿机理将是一种能解释纳秒脉冲高过电压倍数下气体放电现象的理论,对高能量快电子的逃逸运动、碰撞电离引导电子崩的发展等进行了分析,并根据电子能量与阻力关系式,对电子的俘获或逃逸过程进行了计算.结果表明外加场强越高,更多的电子能逃逸,逃逸的能量阈值越低,气压对电子的逃逸过程影响也较大.同时也定性描述了纳秒脉冲下逃逸击穿放电过程.

The runaway breakdown model induced by fast electrons is promising in explaining the nanosecond-pulse breakdown. In this paper, runaway process and collision ionization of fast electrons are discussed. Based on the relations between the electron energy and effective retarding force, the evolution of injected electron energy as a function of distance away from the avalanche head was simulated. The higher applied electric filed strength is,, the lower the runaway energy threshold is and the more fast electrons can runaway, and gas pressures affect the runaway process of fast electrons greatly. Moreover, the runaway breakdown process under the high-voltage nanosecond pulse is described qualitatively.