CAJ | 학술논문

利用102MeV16O6+束轰击同位素靶117Sn，通过熔合蒸发4n反应产生核素129Ce. 由氦喷嘴快速带传输系统将反应产物送到低本底区. 通过化学分离来制备待测的Ce样品，与此同时用16O束轰击117Sn的两种相邻的同位素靶118Sn和116Sn，并比较上述3种反应中的产物来进一步区分元素Ce的不同的同位素. 结果一种半衰期为4.1min的活性被鉴定为129Ce. 基于X-γ-t和γ-γ-t符合测量，建议了包括51条射线在内的129Ce的(EC/β+)衰变纲图. 其中，129Ce基态直接馈送到129La基态的份额(26±7)%是用观测到的129La衰变的278.6keV的γ射线的生长和衰变曲线估计出来的. 另外还给出了用La-Kα-X射线和68.2keV γ射线开门的γ谱以及典型的衰变γ射线的时间谱.
이용102MeV16O6+속굉격동위소파117Sn，통과용합증발4n반응산생핵소129Ce. 유양분취쾌속대전수계통장반응산물송도저본저구. 통과화학분리래제비대측적Ce양품，여차동시용16O속굉격117Sn적량충상린적동위소파118Sn화116Sn，병비교상술3충반응중적산물래진일보구분원소Ce적불동적동위소. 결과일충반쇠기위4.1min적활성피감정위129Ce. 기우X-γ-t화γ-γ-t부합측량，건의료포괄51조사선재내적129Ce적(EC/β+)쇠변강도. 기중，129Ce기태직접궤송도129La기태적빈액(26±7)%시용관측도적129La쇠변적278.6keV적γ사선적생장화쇠변곡선고계출래적. 령외환급출료용La-Kα-X사선화68.2keV γ사선개문적γ보이급전형적쇠변γ사선적시간보.
The nuclide129Ce was produced by a (16O,4n) reaction with an enriched 117　Sn target. With the aid of a helium-jet tape transport system, the reaction products were transported to a shielded location,where Ce samples were prepared after chemical separation. The neighboring isotopes of 117　Sn, 116　Sn and 118　Sn,were also bombarded with 16　O beam. Different isotopes of Ce were further separated by comparing the products in the above three reactions. An activity with a half-life of 4.1 min in the chemically purified cerium samples was identified as 129　Ce. Based on X-γ-t and γ-γ-t coincidence measurements, the EC/β+ decay scheme of 129　Ce, including 51 γ lines,was proposed. Using the observed growth-decay curve of an intense 278.6keV γ line of 129　La decay, the β feeding branch from the ground state of 129　Ce directly to the ground state of 129　La was estimated to be (26±7)%. In addition, the γ spectra gated by both La-Kα-X ray and intense 68.2keV γ ray of 129　Ce decay as well as the time spectra of typical γ rays were also presented here.