https://doi.org/10.1140/epja/s10050-025-01518-4
Regular Article - Experimental Physics
Search for spontaneous fission of 
U, 
U, 
U, and 
U by gamma spectrometry
1
Institute for Nuclear Research of NASU, 03028, Kyiv, Ukraine
2
INFN sezione Roma “Tor Vergata”, 00133, Rome, Italy
3
INFN Laboratori Nazionali del Gran Sasso, 67100, Assergi, AQ, Italy
a dkasper@kinr.kiev.ua, casper.phys@gmail.com
Received:
30
October
2024
Accepted:
13
February
2025
Published online:
10
March
2025
Experimental search for spontaneous fission and cluster decays of U, U, U and U was carried out with a certified 230-g uranium oxide sample enriched in U to 93.2%. The sample was measured over 46.3 days by using a 70 cm
broad energy germanium detector. The search for the fission fragments and their daughters was performed by using 
quanta of energy 
MeV expected in 
decays. No such peaks were observed in the experimental data, thus, upper limits on the fragments’ yields are set. The lower limits on partial half-lives are obtained at the level of 
years for the corresponding cold fission and cluster decay channels. In particular, 5 limits for U and U cold fission exceed the prediction made by S.B. Duarte et al. in framework of the effective liquid drop model by a factor of 1.6–227. Therefore, the obtained results can be used to improve the theoretical frameworks to study the cold fission processes.
B. M. Kropivyansky: Deceased.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
