轴对称静电场的束流光学模拟与设计

Program for beam optical computation of axial symmetrical electrostatic systems

为了对高压倍加器和静电加速器等低能加速器中一些具有特殊结构的轴对称静电元件进行模拟和设计,采用传输矩阵法编写了直流束的束流光学计算程序,并利用该程序对高频离子源预聚焦系统和移动式加速器中子源的束流光学系统进行了模拟和设计。程序将整个轴对称静电场区域看作厚透镜,并均分成若干个小区间,先利用其他电磁场软件计算区域内的轴上电势分布,然后根据该电势分布计算每个小区间内的束流传输情况得到束流的包络曲线。该程序可以用于计算非线性效应可忽略的复杂轴对称静电场中强流和弱流束的传输,且所需计算时间很短。

The beam optical computation of axial symmetrical electrostatic systems is very important in the design and test of low-energy accelerators such as Cock-Croft and Van de Graaf accelerators.In this paper,a program for the beam optical computation of these structures has been developed using transfer matrix method.The electrostatic field region is divided into several small intervals in the program,and then the beam envelope is calculated interval-to-interval from the axial potential distribution,which is calculated by other electromagnetic field simulation software such as Maxwell SV.Space charge effect is included so that the program can be used in the computation of intense beam,while nonlinear effect is beyond its ability.The program can be used in the calculation of beam optics in most complicated axial symmetrical electrostatic fields,and the computing time required is very short.