毛细管式的靶-离子源系统在线实验研究  

Research of the Capillary Target-Ion Source System in On-Line Experiment

作　　者：赵之正[1] 杨永峰[1] 王同庆[1] 郭应祥[1] 郭斌[1] 范红梅[1] 祖凯玲[1] 王旭东[1] 郑兆妙[1] 刘军辉[1] 雷祥国[1] 

机构地区：[1]中国科学院近代物理研究所,兰州730000

出　　处：《高能物理与核物理》2001年第11期1106-1112,共7页High Energy Physics and Nuclear Physics

基　　金：国家重点基础研究发展规划 (G2 0 0 0 0 774 0 0 );国家自然科学基金(1 9875 0 67);中国科学院九五重大项目资助~~

摘　　要：讨论了在线同位素分离器使用激光离子源的必要性 ,分析研究了毛细管式激光离子源对电离器的要求及热毛细管电离器的工作原理 ,并给出了在线实验的结果 .为了在较低温度下形成等离子体鞘势和降低热电离效率 ,采用了低电子逸出功的耐高温材料Nb作毛细管材料 .在线实验获得成功 ,使用毛细管式的靶 -离子源的在线同位素分离器的总效率约达 0 2 % 。In order to study new isotopes and nuclear decay properties in the A>170 mass region, the laser ion source is needed and developed. For on line isotope separator, it is required that the capillary ionization has a speciality of low hot ionization efficiency and high ion extraction efficiency. The principle of the hot capillary ionization was described. The employment of Nb capillary reduces the temperature for forming the plasma potential and inhibitory hot ionization. The ionization tube is made of a Nb capillary of 2.2mm outside diameter, 1.7mm inside diameter and 30mm effective length. The temperature is 1600-2500K when the current is 40-100A. The target chamber is structured by Ta tube of 0.1mm wall thickness and windows of 6μm Ta foil at two ends. Its maximum temperature is 2200K with the current 300A. The test experiment with on line conditions at isotope separator ISOLAND has been performed. 167Yb (T 1/2 17.5min) isotope was produced in nuclear reaction 18O(50MeV/u)+ natTa→ 167Yb. In the condition of target chamber temperature 2130K and capillary temperature 2130K, the total efficiency is 0.2%. This target ion source system will be satisfied in laser ion source.

关 键 词：毛细管电离器 激光离子源 在线同位素分离器 分离效率 热靶 在线实验研究 

分 类 号：O572.2[理学—粒子物理与原子核物理]