⁶⁵Zn is a common calibration source, moreover used as a radioactive tracer in medical and biological studies. In many cases, γ-spectroscopy is a preferred method of ⁶⁵Zn standardization, which relies directly on the branching ratio of Jπ(⁶⁵Zn) = 5/2⁻ → Jπ(⁶⁵Cu) = 5/2⁻ via electron capture (EC*). We measure the relative intensity of this branch to that proceeding directly to the ground state (EC⁰) using a novel coincidence technique, finding I_EC0/IEC* = 0.9684 ± 0.0018. Re-evaluating the decay scheme of ⁶⁵Zn by adopting the commonly evaluated branching ratio of I_β+ = 1.4271(7)% we obtain IEC* = (50.08 ± 0.06)%, and I_EC0 = (48.50 ± 0.06)%. The associated 1115 keV gamma intensity agrees with the previously reported NNDC value, and is now accessible with a factor of ∼2 increase in precision. Our re-evaluation removes reliance on the deduction of this gamma intensity from numerous measurements, some of which disagree and depend directly on total activity determination. The KDK experimental technique provides a new avenue for verification or updates to the decay scheme of ⁶⁵Zn, and is applicable to other isotopes.

⁶⁵ Zn 是一种常见的校准源，此外还用作医学和生物学研究中的放射性示踪剂。在许多情况下，γ能谱是⁶⁵ Zn 标准化的首选方法，它直接依赖于 J π ( ⁶⁵ Zn) = 5/2 ⁻ → J π ( ⁶⁵ Cu) = 5/2 ⁻通过电子捕获的分支比(欧共体*)。我们使用一种新颖的巧合技术测量该分支与直接进入基态 (EC ^{0 ) 的分支的相对强度，发现 I} _EC 0/IEC* = 0.9684 ± 0.0018。重新评估^{65的衰减方案}Zn 采用通常评估的支化比I _β + = 1.4271(7)%，我们得到 IEC* = (50.08 ± 0.06)%，I _EC 0 = (48.50 ± 0.06)%。相关的 1115 keV 伽马强度与之前报告的 NNDC 值一致，现在精度提高了约 2 倍。我们的重新评估消除了对从众多测量中推导出这种伽马强度的依赖，其中一些不同意并直接取决于总活动的确定。^{KDK实验技术为65} Zn衰变方案的验证或更新提供了新途径，并适用于其他同位素。