用时域有限差分法结合PIC粒子模拟方法,对光电子发射引起的圆柱腔内电磁脉冲现象进行了模拟,并对单能电子发射时电场的空间分布和系统电磁脉冲波形特征进行了分析.利用粒子抽样和间隔时间粒子注入的方法,得到了特定电子发射谱下的计算结果,并与非抽样方法所得的结果进行了比较.计算结果显示,采用该方法后,噪声略有增加,但计算要求的条件大大降低,计算的粒子数有效地减少,适用于3维粒子模拟计算;计算结果还显示,发射电子能谱越高,注量越大,表面电场区与饱和电场区的长度越短.

In this paper, the system generated electromagnetic pulse (SGEMP) phenomena caused by photoelectrons emission in cylinder cavity was simulated with FDTD and PIC methods. The characters of electric field waveforms and space distributions were analyzed and summarized in the mono-energetic photoelectron circumstance. Then, with the methods of particle sample and particle emission at a proper interval, the results were obtained when the photoelectrons emit with specific spectrum. At the same time, the results attained from two different particle simulations show that the above methods can decrease the particle numbers involved efficiently except a little bit noise increasing. Therefore, it can be used in the 3-D particle simulation. The results also reveal that the length of strong electric field section decrease with the increasing of the emission electron energy and fluence.