The k0 values of 6 non-1/v nuclides (152Eu, 152mEu, 154Eu, 177Lu, 192Ir and 194Ir) were determined using the extended Høgdahl formalism at the research reactor FRM II with very high f values. Standards were irradiated in 4 channels at different local temperatures between 40 °C and 55 °C measured using temperature sensitive irreversible labels. A good agreement with the recommended values was found for 152Eu, 154Eu and 177Lu using the original g(Tn) factors by Gryntakis, however, the k0 values for 152mEu in this work were 7% higher. New k0 values were also determined using the g(Tn) factors by Van Sluijs. Differences up to 6% were found for Eu isotopes compared with the recommended values. The recommended k0 values for 192Ir and 194Ir could be confirmed using g = 1. The theoretical k0 values for 177Lu were calculated using new nuclear data. They are up to 6% less than the recommended values. The present k0 values determined in this work showed a similar trend. The influence of different g(Tn) factors on the determination of the k0 values was investigated.

中文翻译：

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在 FRM II 下用非常好的热化中子谱测量铕、镥和铱的 k0 值

6 种非 1/v 核素（152Eu、152mEu、154Eu、177Lu、192Ir 和 194Ir）的 k0 值是在研究堆 FRM II 中使用扩展的 Høgdahl 形式化确定的，具有非常高的 f 值。使用温度敏感的不可逆标签在 40 °C 和 55 °C 之间的不同局部温度下，在 4 个通道中辐照标准品。使用 Gryntakis 的原始 g(Tn) 因子发现 152Eu、154Eu 和 177Lu 与推荐值非常吻合，但是，这项工作中 152mEu 的 k0 值高出 7%。Van Sluijs 还使用 g(Tn) 因子确定了新的 k0 值。与推荐值相比，Eu 同位素的差异高达 6%。192Ir 和 194Ir 的推荐 k0 值可以使用 g = 1 来确认。 177Lu 的理论 k0 值是使用新的核数据计算的。它们最多比推荐值低 6%。在这项工作中确定的当前 k0 值显示出类似的趋势。研究了不同 g(Tn) 因素对 k0 值确定的影响。