The 30.8 keV (1/2)${}^{-}$ isomeric state in ${}_{41}^{93}$Nb decays by an $M$4transitiontothe(9/2)$^+$ ground state. We have measured the $K$-shell internal conversion coefficient ${\alpha }_K$ for this transition in order to test the validity of current methods of calculation for a case with relatively low atomic number, low transition energy, and a high value of ${\alpha }_K$. Taking the fluorescence yield of niobium to be 0.751(4), we obtain ${\alpha }_K$ = $2.56(9)\times {10}^4$, a result that agrees with the Dirac-Fock calculations that take into account the presence of a $K$ vacancy in the final state, and disagrees by 1.7 standard deviations with calculations that ignore the vacancy. We also determine the energy of the isomeric state to be 30.760(5) keV, a fourfold improvement in precision over the currently accepted value.

中文翻译：

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93Nb中30.8 keV异构体的M4衰变的K壳内部转化系数

30.8 keV（1/2）${}^{-}$ 处于异构状态 ${}_{41}^{93}$Nb衰减$ M$4Ť\mathrm{[R}\mathrm{一种}ñs\mathrm{一世}Ť\mathrm{一世}ØñŤØŤHË（9/2）$^ + $基态。我们已经测量了$ķ$壳内部转换系数 ${\alpha }_{ķ}$ 为了测试当前计算方法在原子序数相对较低，跃迁能量较低且α值较高的情况下的有效性， ${\alpha }_{ķ}$。以铌的荧光产量为0.751（4），我们得到${\alpha }_{ķ}$ = $2.56（9）\times {10}^4$，该结果与Dirac-Fock计算相符，该计算考虑了 $ķ$最终状态下的空缺，并且与忽略空缺的计算不同意1.7个标准差。我们还将异构体的能量确定为30.760（5）keV，比目前接受的值精度提高了四倍。