https://doi.org/10.1140/epja/s10050-024-01383-7
Regular Article - Experimental Physics
Isomer production studied with simultaneous decay curve analysis for alpha-particle induced reactions on natural platinum up to 29 MeV
1
Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, 1400, Wien, Austria
2
Nishina Center for Accelerator-Based Science, RIKEN, 351-0198, Wako, Japan
3
HUN-REN Institute for Nuclear Research (ATOMKI), 4026, Debrecen, Hungary
4
Faculty of Science, Hokkaido University, 060-0810, Sapporo, Japan
5
Graduate School of Biomedical Science and Engineering, Hokkaido University, 060-8638, Sapporo, Japan
6
Global Center for Biomedical Science and Engineering, Faculty of Medicine, Hokkaido University, 060-8648, Sapporo, Japan
7
Graduate School of Science and Engineering, Saitama University, 338-8570, Saitama, Japan
Received:
26
April
2024
Accepted:
14
July
2024
Published online:
27
September
2024
The isomeric ratios of 
Au, 
Hg and 
Hg produced by 
-particle induced reactions on natural platinum were investigated experimentally up to 29 MeV by using the standard stacked foil activation technique and 
-ray spectrometry. The isomeric ratios of Hg and Hg determined by the conventional activation cross section formula showed strong cooling time dependence. The time dependence was resolved by adjusting the isomeric transition branching ratios for the two isotopes within a simultaneous decay curve analysis framework. Our analysis suggests 94.5±0.7% and 48.9±1.8% as the isomeric transition branching ratios of 
Hg (24 h) and 
Hg (42 h), respectively. The isomeric ratios and independent production cross sections of Au, Hg, Hg and some other Hg, Au and Pt isotopes were also measured down to 6 MeV with these corrected isomeric transition branching ratios, and compared with predictions of statistical and pre-equilibrium models by TALYS-2.0 to discuss spin cutoff parameter dependence. We found the measured isomeric ratios are better predicted if we reduce the spin cutoff parameter to half or less from that estimated with the rigid body moment of inertia.
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© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2024. 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.
