^(130)Ce(EC+β^+)衰变研究及其放射化学分离  

(EC+β^+) decay study of ^(130)Ce and it's radiochemical separation

作　　者：张天梅[1] 杜金洲[2] 徐树威[1] 谢元祥[1] 李占魁[1] 

机构地区：[1]中国科学院近代物理研究所,兰州730000 [2]兰州大学现代物理系,兰州730000

出　　处：《核技术》2002年第1期9-14,共6页Nuclear Techniques

基　　金：国家自然科学基金 (19775 0 5 5 );中国科学院"八五"重大项目课题 (KJ85 - )资助

摘　　要：利用兰州SFC加速的16O束轰击同位素118Sn ,由熔合蒸发 4n反应产生目标核13 0 Ce。为了消除本底干扰并指定13 0 Ce核 ,采用溶剂萃取法对He - jet带传输系统从靶室传输出来的反应产物进行了离线分离与纯化。将目标核13 0 Ce从大量的靶材料、反应产物及母核中分离出来 ,快速制成薄源后在铅室中进行γ单谱测量及X -γ、γ -γ符合测量。从化学分离后的产物中观察到了半衰期为 2 2 .9min的 10 8条γ射线 ,其中 10 7条是新发现的 ,该活性被指定为13 0 Ce。在此基础上 ,进一步研究这些γ线的级联关系 ,建立了缺中子同位素13 0 Ce较完整的 (EC + β+ )衰变纲图。为118Sn(16O ,4n) 13 0 Ce反应体系建立的放化分离流程的分离时间仅 10min ,化学产额大于70 %。化学分离除去 98%以上的核反应生成的13 0 La ,对其它杂质的去污完全满足13 0 Ce(EC + β+ )衰变研究的要求。The nuclide 130 Ce was produced by a ( 16O,4n) reaction carried out at the SFC accelerator of IMP on an enriched 118 Sn target. Reaction products were moved to a shielded location by a He-jet tape-transport system, then using a radiochemical separation procedure in which a solvent extraction and precipitation with oxalic acid method was applied, Ce was separated, purified and made into thin sample rapidly, and then a single spectrum as well as X-γ, γ-γ coincidence measurements was performed . A 22.9min activity in chemical separated sample was identified as 130 Ce. The decay scheme was proposed for the first time. The scheme included 108 lines of γ rays, among which 107 being new. Total separation time of this new chemical procedure was about 10min, and the chemical yield was about 70%. More than 98% La produced in nuclear reaction was removed, decontamination of other impurities also satisfied the requirement of study of 130 Ce (EC+β +) decay scheme.

关 键 词：Β衰变 纯化 放射化学 分离 铈130 缺中子核 核衰变纲图 

分 类 号：O571.322[理学—粒子物理与原子核物理] O615.11[理学—物理]