Improvement of gross theory of beta-decay for application to nuclear data

Hiroyuki Koura, Tadashi Yoshida, Takahiro Tachibana, Satoshi Chiba

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)


A theoretical study of β decay and delayed neutron has been carried out with a global β-decay model, the gross theory. The gross theory is based on a consideration of the sum rule of the β-strength function, and gives reasonable results of β-decay rates and delayed neutron in the entire nuclear mass region. In a fissioning nucleus, neutrons are produced by β decay of neutron-rich fission fragments from actinides known as delayed neutrons. The average number of delayed neutrons is estimated based on the sum of the β-delayed neutron-emission probabilities multiplied by the cumulative fission yield for each nucleus. Such a behavior is important to manipulate nuclear reactors, and when we adopt some new high-burn-up reactors, properties of minor actinides will play an important roll in the system, but these data have not been sufficient. We re-analyze and improve the gross theory. For example, we considered the parity of neutrons and protons at the Fermi surface, and treat a suppression for the allowed transitions in the framework of the gross theory. By using the improved gross theory, underestimated half-lives in the neutron-rich indium isotopes and neighboring region increase, and consequently follow experimental trend. The ability of reproduction (and also prediction) of the β-decay rates, delayed-neutron emission probabilities is discussed. With this work, we have described the development of a programming code of the gross theory of β-decay including the improved parts. After preparation finished, this code can be released for the nuclear data community.

Original languageEnglish
Title of host publicationND 2016
Subtitle of host publicationInternational Conference on Nuclear Data for Science and Technology
EditorsPeter Siegler, Wim Mondelaers, Arjan Plompen, Franz-Josef Hambsch, Peter Schillebeeckx, Stefan Kopecky, Jan Heyse, Stephan Oberstedt
PublisherEDP Sciences
ISBN (Electronic)9782759890200
Publication statusPublished - 2017 Sept 13
Event2016 International Conference on Nuclear Data for Science and Technology, ND 2016 - Bruges, Belgium
Duration: 2016 Sept 112016 Sept 16

Publication series

NameEPJ Web of Conferences
ISSN (Print)2101-6275
ISSN (Electronic)2100-014X


Other2016 International Conference on Nuclear Data for Science and Technology, ND 2016

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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