完全匹配层吸收边界在2D3V等离子体粒子模拟中的实现

Implementation of PML absorbing boundary in 2D3V PIC simulation

基于Berenger完全匹配层的基本思想,导出了高斯单位制下2维完全匹配层吸收介质的控制方程及参数设置方法,并进行了数值验证和参数优化。依据所得结论编制了相应的吸收边界模块加入到2D3V等离子体粒子模拟程序PLASIM中,取得了良好的吸收效果。基于完全匹配层吸收边界的实现,在小窗口内对超强激光预脉冲与低密度等离子体的长时间相互作用过程进行了模拟研究,结果表明:激光强度和作用时间是影响等离子体密度改变的重要因素,超强激光其长时间的预脉冲可以通过有质动力的累积效应在低密度等离子体中引起较大的密度变化。

The perfectly matched layer（PML） medium equations for Gaussian unit were derived based on the basic idea of Benrenger＇s PML and the numerical validation and parameter optimization were done.The corresponding absorbing boundary module was added into the 2D3V PIC software PLASIM,achieving good absorption with low reflection.In addition,this module is proved applicable by simulating the propagation of a nanosecond laser prepulse in an underdense plasma.