Experimental k_0 and k_0-fission factors for the determination of the n(~(235)U)(~(238)U) enrichment levels and correction for ~(235)U fission interferences in samples containing uranium

摘要

In 2010 we investigated the applicability of the current k_0 and k_0-fission factors for the determination of the n(~(235)U)(~(238)U) isotopic ratio in multi-elemental samples containing uranium. An overestimation 3-4 % was observed in our determinations when employing the recommended 2003 k_0-literature. After a recalibration of all our laboratory instruments, a 3 % overestimation was still observed in this work when employing this nuclear data. Therefore we aimed at the experimental re-determination of these composite nuclear constants in order to enhance the reliability of the isotopic ratio determination method and the accuracy of our data-filtering algorithms. New k_0-fission factors are given for 7 nuclides that are not currently present in the 2012 k_0-database. Several additional k_0 factors are introduced for some nuclides in this library. Our k_0 results are also compared with those recently reported by Blaauw et al.