基于BEM泊松方程求解的空间电荷效应数值模拟

 为了模拟强束流在加速器及其传输线中的行为，用C++语言开发了一种包含空间电荷效应的多粒子跟踪程序(PTP-SC)，它在经典的PIC方法基础上，基于边界元法(BEM)和非等距的网格求解泊松方程。束流在自由空间分布的仿真结果与解析结果保持较好的一致性。给出了一条注入线的模拟计算结果，并与ORBIT,TRACE 3-D的计算结果进行比对。结果表明：该程序与采用数值方法的ORBIT程序的计算结果有较好的一致性。该程序可用于直线加速器及回旋加速器中的空间电荷效应模拟。

Numerical Simulation of Space Charge Effect with BEM Poisson Solver

The general property of space charge dominated beam behavior is that a beam with an initial non-linear profile tends to become more uniform and this process is associated with strong emittance and the appearance of beam halo which are the potential sources of beam loss in high intensity accelerators. To simulate the beam behavior, a general particle tracking code including space charge effect was implemented using C++ language. Based on the classical PIC method, this code employs the boundary element method as the Poisson solver to compute space charge force with non-equidistant multi-grid. The comparison of simulative and analytical results of the beam distribution in free space shows good consistency. Finally, the simulative result of an injection beam line is presented. The computation