M. Verpelli | Searcharxiv

arXiv2022

Systematic Trends of 0$^+_2$, 1$^-_1$, 3$^-_1$ and 2$^+_1$ Excited States in Even-Even Nuclei

The spin and parity ($J^{\pi}$) assignments in even-even nuclei were reviewed across the nuclear chart using the Evaluated Nuclear Structure Data File (ENSDF). The prevalence of 2$^+_1$ first or lowest excited states is confirmed. The properties of 0$^+_2$, 1$^-_1$, and 3$^-_1$ lowest excited states were reexamined using the ENSDF data evaluation procedures. The $J^{\pi}$ systematic trends and correlations between level quantum numbers and nuclear physics phenomena are discussed.

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arXiv2021

Development of a Reference Database for Beta-Delayed Neutron Emission

Beta-delayed neutron emission is important for nuclear structure and astrophysics as well as for reactor applications. Significant advances in nuclear experimental techniques in the past two decades have led to a wealth of new measurements that remain to be incorporated in the databases. We report on a coordinated effort to compile and evaluate all the available beta-delayed neutron emission data. The different measurement techniques have been assessed and the data have been compared with semi-microscopic and microscopic-macroscopic models. The new microscopic database has been tested against aggregate total delayed neutron yields, time-dependent group parameters in 6-and 8-group re-presentation, and aggregate delayed neutron spectra. New recommendations of macroscopic delayed-neutron data for fissile materials of interest to applications are also presented. The new Reference Database for Beta-Delayed Neutron Emission Data is available online at: http://www-nds.iaea.org/beta-delayed-neutron/database.html.

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