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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。
I. INTRODUCTION With the expansion of the application range of ion source, the requirements for the stability of its work are also getting higher and higher. In order to improve the working characteristics of the ion source, the stability of the discharge parameters must be maintained. The discharge parameters depend mainly on the discharge current, magnetic field and discharge chamber pressure. Among them, the stability of pressure on the discharge plasma density, the ion beam extraction, proton ratio and the number of ionic charge the most obvious. It can be seen from Fig. 1, 2, 3 and 4 that under the optimal pressure, the ion density, proton ratio and ion beam current show the peak value, and the optimum value decreases obviously on both sides. In general, ion sources all hope to choose the best pressure to work. Therefore, maintaining the stability of the pressure is very important. This is especially true for DC sources.