摘要
基于计算电磁学中对强迫激励源消除虚假反射的算法分析,提出了用等效电流和等效磁流在FDTD公式中引入电场激励源和磁场激励源的方法。从粒子模拟方法的基本方程和迭代公式出发,分析了激励源的引入过程,推导出激励源所等效的电流项和磁流项表达式,实现了新的激励源设置方法,并进行了数值验证和结果讨论。研究表明:这类等效模型与标准FDTD公式能紧密结合,引入非常方便;不必专门设置一个附加的散射场区来处理散射场的计算,大大节省了计算时间和计算内存,比常规总场/散射场体系方法的效率高20%以上,对粒子模拟这类耗时的计算较为适用。通过对2维柱坐标系下相对论速调管放大器(RKA)的模拟,证明了此类激励源设置方法的实用性。
This paper analyzes the equivalent current method in FDTD for excitation source design. The method is based on the method for avoiding the unwanted non-physical scattering fields in computational electromagnetics. It excites electromagnetic fields by introducing equivalent electric or magnetic current into FDTD formulae. The analysis of the excitation source technology in PIC simulation and the formulae of the new method are also provided. According to the theoretical analysis, the new method has a compact form and can be easily introduced into FDTD formulae for numerical realization. According to the numerical validation, the new method needn＇t set an addisional scattering field region for scattering field calculation specially, and it has more than 20 % higher efficiency and obvious lower requirement of computer memory than general excitation source methods based on the total/scattering field system, so it＇s very suitable for some time-consuming electromagnetic calculations such as PIC simulation. Further more, the practicability of this method is proved by computing relativistic klystron amplifier （RKA） in 2D cylindrical coordinate system as an example.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2007年第5期790-794,共5页
High Power Laser and Particle Beams
基金
国家863计划项目资助课题
关键词
FDTD法
粒子模拟
激励源
等效电流
等效磁流
FDTD method
PIC simulation
Excitation source
current Equivalent electric current
Equivalent magnetic
