低能强流混合离子束空间电荷补偿度研究  

Space Charge Compensation Study of Low-energy High-intensity Mixed Ion Beams

作　　者：申圳 孙良亭[1,2] 冯玉成 李立彬[1] 刘俊亮 赵红卫[1,2] Zhen SHEN;Liangting SUN;Yucheng FENG;Libin LI;Junliang LIU;Hongwei ZHAO(Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;School of Nuclear Science and Technology,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院近代物理研究所,兰州730000 [2]中国科学院大学核科学与技术学院,北京100049

出　　处：《原子核物理评论》2023年第1期45-50,共6页Nuclear Physics Review

基　　金：国家自然科学基金资助项目(11427904,12025506)。

摘　　要：空间电荷效应是影响束流传输和束流品质的一个重要因素,特别是对于低能量强流离子束来说。离子束与束流传输线中的剩余气体分子通过电离反应等产生大量二次电子,受离子束的空间电势约束,可以部分补偿空间电荷效应。为了深入研究强流束在低能段的传输,需要准确测量束流的空间电荷补偿度(SCCD),尤其是混合束流的SCCD。利用一台三栅网式能量分析仪和一台基于128通道皮安表系统构成的束流剖面探测器,分别测量了不同流强和束流分布下的混合O离子束的二次离子能量分布和束流流强分布,从而计算得出SCCD。实验结果表明,在1.0×10^(−5) Pa的真空度下,不同流强的混合O离子束的SCCD基本在70%左右;不同束流分布对空间电势分布影响较大,对离子束的SCCD也会有一定程度的影响。The space charge effect is one of the key factors affecting ion beam transport and ion beam quality,especially for low-energy high-intensity ion beams.It can be partially compensated by the secondary electrons,which are produced from the ionization of residual gas molecules in the beam pipe and trapped by the space charge potential of ion beams.To study high intensity beam transport in low energy section,it is essential to have an accurate value of space charge compensation degree(SCCD)of the beam,particularly for mixed ion beams.Using a three-grid energy analyzer and a beam profile monitor based on an 128-channel picoammeter system,we measured the secondary ion energy distribution and the beam current distribution of mixed oxygen ion beams of different beam intensities and beam distributions,respectively.Thus the SCCD of the beams can be calculated.The results show that for mixed oxygen ion beams of different intensities,the SCCD are basically around 70%under the vacuum of 1.0×10^(−5) Pa;The space charge potential of the beams are affected greatly by the beam current distributions,which also consequently have influence on the SCCD of the ion beams.

关 键 词：混合离子束 空间电荷补偿度 二次离子能谱 束流剖面探测器 

分 类 号：O571.53[理学—粒子物理与原子核物理]