Department of Chemistry, Michigan State University, East Lansing, MI, 48824, USA; National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
Appl Radiat Isot. 2022 Jan;179:109994. doi: 10.1016/j.apradiso.2021.109994. Epub 2021 Oct 22.
A sample of Ca produced through isotope harvesting at the National Superconducting Cyclotron Laboratory was used to measure branching ratios of 7.17(5)%, 7.11(5)%, and 75.0(5)% for the 489.2, 807.9, and 1297.1 keV characteristic gamma rays, respectively. Based on these updated branching ratios, the ground state to ground state Ca to Sc beta decay branching ratio has been indirectly measured as 17.7(5)% and the ground state to 1297.1 keV excited state as 82.2(5)%. These values represent a greatly increased precision for all five branching ratios compared to the currently accepted values (Burrows, 2007). The measurements presented here were made relative to the ingrown Sc daughter in aCa sample and the well-established 159.4 keV gamma-ray branching ratio and the half-life for the decay of Sc (Reher et al., 1986; Meadows and Mode, 1968; Mommsen et al., 1980). These measurements were supported by verifying that the half-lives measured from characteristic gamma-ray peaks over multiple spectra for both Ca and Sc were consistent with previously reported values. Additionally, the half-lives of both Ca and Sc were independently measured with Liquid Scintillation Counting to reverify the previously reported values used in this study to find updated gamma-ray branching ratio values.
在国家超导回旋加速器实验室通过同位素收获得到的 Ca 样品用于测量 489.2keV、807.9keV 和 1297.1keV 特征伽马射线的分支比，分别为 7.17(5)％、7.11(5)％和 75.0(5)％。基于这些更新的分支比，间接测量了基态到基态 Ca 到 Sc 的β衰变分支比为 17.7(5)％，基态到 1297.1keV 激发态为 82.2(5)％。与目前公认的值（Burrows，2007）相比，所有五个分支比的精度都大大提高。这里呈现的测量结果是相对于 Ca 样品中的内生长 Sc 子体进行的，同时还参考了确立已久的 159.4keV 伽马射线分支比以及 Sc 衰变的半衰期（Reher 等人，1986；Meadows 和 Mode，1968；Mommsen 等人，1980）。通过验证在 Ca 和 Sc 的多个光谱中从特征伽马射线峰测量的半衰期与先前报道的值一致，支持了这些测量。此外，还使用液体闪烁计数法独立测量了 Ca 和 Sc 的半衰期，以验证用于本研究的先前报道的值，以找到更新的伽马射线分支比值。
