Abstract

The first cycle of measurements of the ratio of cumulative spectra of beta particles originating from the isotopes \({}^{235}\)U and \({}^{239}\)Pu undergoing thermal-neutron-induced fission was performed. It is found that the curve obtained from our present measurement of the \({}^{235}\)U\(/^{239}\)Pu ratio of beta-particle spectra lies 5\({\%}\) lower than the analogous curve following from the measurement of a group from Institute Laue–Langevin (ILL). The present analysis reveals that this is due to an erroneous 5\({\%}\) overestimation of the \({}^{235}\)U beta-particle spectrum measured by the ILL group. As a consequence, the results obtained for the \({}^{235}\)U \(\bar{{\nu}}_{e}\) spectrum at the production instant via a reconstruction from the cumulative spectrum of beta particles from \({}^{235}\)U also turned out to be overestimated by 5\({\%}\). These data explain the effect of the reactor antineutrino anomaly.

中文翻译：

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用于解决反应堆-反中微子物理问题的$$ {} ^ {{235}} $$ U和$$ {} ^ {{239}} $$ Pu裂变产物中β粒子累积光谱之比的测量

摘要

进行了第一个循环的测量，这些循环是由热中子诱发裂变的同位素\（{} ^ {235} \） U和\（{} ^ {239} \） Pu生成的β粒子的累积光谱之比。发现从我们目前对β粒子光谱的\（{} ^ {235} \） U \（/ ^ {239} \） Pu比的测量得出的曲线为5 \（{\％} \）低于Laue–Langevin研究所（ILL）的一组测量结果得出的类似曲线。本分析表明，这是由于ILL组测得的\（{} ^ {235} \） Uβ粒子光谱错误5 \（{\％} \）高估了。结果，对于通过根据来自\ {{} ^ {235的beta粒子的累积光谱进行重建，在生产瞬间\（{} ^ {235} \） U \（\ bar {{\ nu}} _ {e} \）光谱} \） U也被高估了5 \（{\％} \）。这些数据解释了反应堆抗中微子异常的影响。