用串列静电加速器获取MeV高能团簇离子束  

Extraction of MeV high energy cluster beams using tandem accelerator

作　　者：张卫东[1] 裘元勋[1] 孙传琛[1] 贺勉鸿[1] 

机构地区：[1]复旦大学现代物理研究所,应用离子束核物理实验室,上海200433

出　　处：《核技术》2000年第2期94-100,共7页Nuclear Techniques

基　　金：核工业科学基金

摘　　要：利用复旦大学现有的串列静电加速器（ＮＥＣ９ＳＤＨ—２）获得了能量为１—４ＭｅＶ的硼、碳、硅及金等小型高能团簇离子束：Ｂｎ＋（ｎ＝２）、Ｃｎ＋（ｎ＜１０）、Ｓｉｎ＋（ｎ＝２，３，４）以及Ａｕｎ＋（ｎ＝２）；束流强度与团簇的种类和所含的原子数有关，为０．１—１００ｎＡ量级。注入加速器的低能团簇负离子由铯溅射离子源（ＳＮＩＣＩＩ）产生，高能团簇正离子的质量鉴别用磁分析器完成。高能碳团簇负离子Ｃ８－在与剥离气体分子Ｎ２碰撞过程中形成的团簇碎片质量谱显示出与碳团簇结构有关的奇偶效应。Small cluster ions such as B_n^+ (n = 2), C_n^+ (n < 10), St_n^+ (n = 2,3,4) and Au_n^+ (n= 2)have been accelerated to 1-4 MeV in the 3×2MV tandem pelletron of FudanUniversity (NEC 9SDH2). Intensities of the MeV cluster beams ranging from 0.1 to100nA depend on the type of cluster ions and the number of atom it contains. The lowenergy negative cluster ions injected were obtained from a cesium sputter source(SNICS II). The mass analysis of the high energy cluster beams was performed by aswitching magnet. The mass spectrum of the carbon cluster beam produced in thecollisions of C_8^- cluster ions with stripping gas molecules N_2 indicates that there isan odd-even effect related to the carbon cluster styucture.

关 键 词：碳团簇 串列静电加速器 MeV高能团簇离子束 

分 类 号：TL52[核科学技术—核技术及应用] O572.211[理学—粒子物理与原子核物理]