静电加速器的周期聚焦效应

从理论分析及在电解槽中进行模拟实验测量知道,静电加速器加速管内的电场分布一般不是均匀的,而是有周期性变化的。本文利用微扰法求解了离子束在这种周期场内运动的傍轴轨迹方程,描绘出了离子束在这种场内的轮廓,也求出了表达这个离子光学系统的焦距公式,并讨论了空间电荷效应对离子束的发散作用。

PERIODIC FOCUSING EFFECT IN DC ACCERLERATORS

The ion-optical properties of the accerlerating tube made of a series of coaxial cylinders in a DC accerlerator have been investigated. The potential distribution in such an accerlerating tube has been found both theoretically and experimentally by means of an electrolytic trough. The field in the accerlerating tube is found to be not exactly uniform as usually considered but it should also consist of a periodic part.The paraxial-ray equation for describing the ion trajectory in such a periodic field has been solved. The profile of the ion beam does show an undulatory shape, especially in the low energy region. The periodic field produces a significant focusing effect. A formula for describing the focal length of the ion-optical system was derived. The space charge effect has also been considered.