Compilation and Evaluation of Beta-Delayed Neutron Emission Probabilities and Half-Lives for Z > 28 Precursors

Development of a Reference Database for Beta-Delayed Neutron Emission

“…This was done in Ref. [106] for the case of 137 I, and a good agreement was found with the P 1n value recommended in this CRP [36] (see Table I).…”

“…However, in a similar work reported in Ref. [108], the P 1n value obtained for 137 I was 11% smaller, while the value for 95 Rb was found to be 22% larger than the evaluation [36]. It is clear from this that further work is needed, both experimentally and from the point of view of simulations, to clarify the situation and establish the systematic uncertainties of the method.…”

“…Currently (as of August 2020) 653 nuclei between 8 He and 237 Ac have been identified as potential β-delayed oneneutron emitters (Q β1n > 0 keV). However, as of August 2020 only 306 of those nuclei have measured β-delayed one-neutron branching ratios (P 1n ): 114 in the light mass region Z < 28 [35], 183 in the fission fragment region (Z = 29 − 57), and 9 in the region above Z > 57 [36]. A total of 28 of these measurements provided only an upper limit for the P 1n value, and another six provided only lower limits.…”

“…The collaboration will conclude its experimental campaigns in 2021 and is expected to add in the near future > 250 new β-delayed neutron emitters to the existing list. The data from the experimental runs in 2016-19 is presently being analyzed, and a small fraction has already been published and included in the latest Z > 28 evaluation [36]. An overview of the BRIKEN and future campaigns can be found in Sect.…”

“…These pictures include the vast amount of measurements that were performed during the course of the evaluation work that has been published in Refs. [35,36] (see following Sect. III), as well as the majority of the (yet unpublished) data from the BRIKEN project [37,51] which will conclude its campaign in 2021.…”