强流束在三圆筒单透镜中的传输研究

A Study of Intense Pulsed Beam Transfer in Three-tube Einzel Lenses

强流脉冲束在三圆筒单透镜中的传输是一个相当复杂的问题,因为不同类型的粒子束分布产生不同的空间电荷场,而在束流运动过程中,空间电荷场也在不断地变化,而且粒子运动的轨迹与空间电荷势又是相互依赖的,因此需要求得一个自洽的解。对于强流脉冲束在三圆筒单透镜中的传输,束流的空间电荷效应显著,需要考虑空间电荷效应对束流传输的影响。采用矩阵法分析非强流脉冲束流与强流脉冲束流在三圆筒单透镜中的传输矩阵,采用迭代方法计算强流脉冲束流的空间电荷效应对束流传输的影响,并编写了束流在三圆筒单透镜等元件中传输的计算程序。程序在进行模拟计算时,可以直观地显示束流相图、束流包络线等图形。

The transfer of intense pulsed beams in three-tube einzel lenses is a very complicated issue, because particle beam distributions of different types may cause different space-charge fields while particle trajectories and space charge potentials are mutually dependable with changes of space-charge fields in the process of particle beam motion. So, it is necessary to solve the problem by getting self-consistent solutions. Space-charge effects on the intense pulsed beam transfer should be considered, because when the intense pulsed beam is transferred in the three-tube einzel lenses, the space-charge effects of intense pulsed beam is obvious. The paper uses the ma- trix method to analyze the transfer matrix of non-intense pulsed beams and intense pulsed beams respectively in three-tube einzel lenses, and by using the iteration calculates the space-charge effects of the intense pulsed beam on the transfer of particle beams. Through designing a calculation program for the particle beam transfer in three-tube einzel lenses, we can clearly show the beam phase diagram and the envelope curve.