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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 isotope 118Sn was bombarded with 16O beams accelerated by SFC in Lanzhou, and the target nucleus 13 0 Ce was generated by fusion evaporation 4n reaction. In order to eliminate the background interference and designate a 13 Ce nucleus, the reaction products transferred from the target chamber by He - jet belt transport system were separated and purified by solvent extraction. The target nucleus 13 Ce was isolated from a large amount of target materials, reaction products and mother nuclei. After rapid thinning, γ mono-spectrum measurements and X-γ and γ-γ coincidence measurements were performed in a lead chamber. From the products after chemical separation, 10 8 γ-rays with a half-life of 22.9 min were observed, of which 10 7 were newly discovered and the activity was designated as 13 0 Ce. On the basis of this, we further study the cascade relationship of these γ-rays, and establish a complete (EC + β +) decay scheme of neutron isotope 13 0 Ce. The separation time for the radiochemical separation process established for 118Sn (16O, 4n) 13 0 Ce reaction system was only 10 min and the chemical yield was more than 70%. Chemical separation removes more than 98% of the 13 La generated by nuclear reactions, and the decontamination of other impurities completely satisfies the requirement of the 13 0 Ce (EC + β +) decay study.