关于离子源供气气压稳定性的探讨

APPROACH CONCERNING STABILITY OF GAS PRESSURE IN ION SOURCE

摘要: <正> 一、前言随着离子源应用范围的扩展,对其工作稳定性的要求也越来越高。为改善离子源的工作特性,必须维持放电参数的稳定。放电参数主要取决于放电电流、磁场和放电室气压。其中,气压的稳定性对放电等离子体密度、引出离子束流、质子比及离子电荷数的影响最为明显。由图1,2,3,4可见,在最佳气压下,离子密度、质子比、引出离子束流出现峰值,最佳值两侧则明显下降。通常,离子源都希望选在最佳气压下工作。因此,保持气压的稳定性十分重要。对于直流工作状态的离子源尤其如此。

Abstract: The influence of gas pressure on stability of an ion source operation isdiscussed Experiments on the gas pressure stability of the pulsed duoplasmatron mounted in the 10 MeV proton linac are made. When hydrogensupply for the pulsed duoplasmatron by an ultra-pure hydrogen generator incorpo-rated with the mass flow controller, or with the gas steady-pressure valve, orwith both of them, the results of the experiment is satisfactory. The pressurestability rise from 8% to<1%. The pressure is very stable when the pulsedduoplasmatron operate continuously.