关键词: 
EC/β+衰变 /
氦喷嘴快速带传输系统 /
衰变纲图 /
同核异能态 

摘要: 利用187 MeV的⁴⁰Ca离子轰击同位素靶⁹²Mo， 由熔合蒸发反应生成目标核¹²⁶Ce。 藉助氦喷嘴快速带传输系统和X-X-t与X-γ-t符合测量， 首次建立了¹²⁶Ce的EC/β+衰变纲图。 建议了可能属于¹²⁶Ce一个高自旋同核异能态的衰变， 其β衰变后布居在与¹²⁶La的高自旋同核异能态相关的低位能级区， 测定的半衰期是57(9) s。 也建议了可能属于¹²⁶Ce基态的衰变， 其β衰变后布居在与¹²⁶La的低自旋同核异能态相关的低位能级区，它的半衰期被测定为12(4) s。 但偶偶核¹²⁶Ce存在高自旋同核异能态的物理原因还有待进一步探究。 Ce was produced by bombarding an enriched target of ⁹²Mo with 187 MeV ⁴⁰Ca beam and studiedby using a heliumjet fast tape transport system in combination with X-γ and γ-γ coincidencemeasurements. An EC/β⁺ decay scheme of ¹²⁶Ce was proposed for the first time. A group of lowlying states associated with the lowspin isomer in ¹²⁶La feeding by β decay was possibly from the groundstate EC/β⁺ decay of ¹²⁶Ce with the measured half-life 12(4) s. Another group of lowlying states associated with the highspin isomer in ¹²⁶La feeding by β decay was possibly from a highspin isomer EC/β⁺ decay of ¹²⁶Ce with the measured half-life 57(9) s. However， the physical reason for the existence of a highspin isomer in even-even nucleus ¹²⁶Ce is still an open problem.