MEVVA源引出离子束流分布均匀性的初步研究

通过采用加会切磁场、增大离子源阴极与阳极距离并限制源等离子体发射角，从而使源阳极电位高于等离子体电位和采用改变源阳极结构──仅用阳极筒──从而改变弧放电路径这３种方法，对改善ＭＥＶＶＡ源引出离子束流密度分布的均匀性进行了初步的研究。第３种方法从根本上改变了ＭＥＶＶＡ源引出束分布的高斯分布特性，在合适的条件下可能得到更为均匀的束流密度分布。

A STUDY ON THE HOMOGENEITY OF ION BEAM DISTRIBUTION EXTRACTED FROM MEVVA ION SOURCE

The distribution of ion beam density extracted from a MEVVA ion source is studied by three methods. The first is using a cusped magnetic field; the second is increasing the distance between the cathode and the anode of the MEVVA source and confining the emitting angle of the plasma so that the potential of the anode is higher than that of the plasma; the third is changing the anode structure of the MEVVA ion source so as to change the route of the vacuum are.Experimental results suggest that the third approach can give more homogeneous distribution of beam density under proper working conditions.