Computational Design Studies for an Ion Extraction System for a ''volume-type'' ECR Ion Source
Computational Design Studies for an Ion Extraction System for a ''volume-type'' ECR Ion Source
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DOI：
10.1063/1.1430511
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发表时间：
2001-11
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影响因子：
--
通讯作者：
H. Zaim
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文献类型：
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作者：
H. Zaim
为了从配备三电极提取系统的全永磁体“体积型”ECR离子源中最佳提取高强度、空间电荷有限的多电荷离子束，进行了数值研究。这些研究清楚地表明，为了确保高质量、最小发散（高度可转移）的离子束，能够调整提取间隙的重要性。当等离子体半月板具有给定电流密度的最佳曲率时，达到最佳提取条件。发现最佳性能（最佳电流）值与提取空间电荷主导光束的基本解析理论所得值非常吻合。电极系统设计的细节以及角散度和RMS发射度与提取参数数据（例如，性能和提取间隙）提供了不同电荷状态和质量的离子束，在镜像几何等离子体约束磁场的影响下提取。
Numerical studies have been performed for optimally extracting high-intensity, space-charged-limited multi-charged ion beams from an all-permanent-magnet, ''volume-type'' ECR ion source, equipped with a three-electrode extraction system. These studies clearly demonstrate the importance of being able to adjust the extraction gap in order to ensure high quality, minimum divergence (highly transportable) ion beams. Optimum extraction conditions are reached whenever the plasma meniscus has an optimum curvature for a given current density. Optimum perveance (optimum current) values are found to closely agree with those derived from elementary analytical theory for extraction of space-charge-dominated beams. Details of the electrode system design as well as angular divergence and RMS emittance versus extraction parameter data (e.g., perveance and extraction gap) are provided for ion beams of varying charge-state and mass, extracted under the influence of a mirror-geometry plasma confinement magnetic field.