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。
126Ce was produced by bombarding an enriched target of 9ZMo 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 126 La feeding by 13 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 126 La feeding by t3 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.
参考文献
| [1] | BOGDANOV D D, DEMYANOV A V, KARNAUKHOV V A, etal. NuclPhysA, 1978, 307: 421. |
| [2] | GENEVEYJ, GIZON A, IDRISSI N, etal. Proc of the 5th lnt Conf On Nuclei far from Stability, Rosseau Lake, Cana- da, 1987, 419. |
| [3] | ASAI M, KOJIMA Y, OSA A, etal. JAERI, Takasaki Ion Accelerators for Advanced Radiation Application, Annual Re- port, 1993, 3:171. |
| [4] | KOJIMA Y, ASAI M, SHIBATA, et al. Applied Radiation and Isotopes, 2002, 56: 543. |
| [5] | MAR J, GIZON A, PARIS P, et al. Eur Phys J A, 2000, 7-7. |
| [6] | KATAKURA J, KITAO K. NUCLEAR Data Sheets, 2002, 97: 902. |
| [7] | NAZAREWICZ W, DUDEK J, BENGTSSON R, etal. Nucl Phys A, 1985, 435 - 397. |
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