Incomplete fusion reaction producing 234U, 233U, and 232U in the 232Th + 7Li reaction
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Ayumu Nagai
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Akihiro Nambu
Abstract
The nuclide of 237Np (t 1/2 = 2.1 × 106 y), produced in nuclear facilities, is important because its investigation is relevant to environmental pollution and material cycling in earth sciences. It is expected to be analyzed by mass spectrometry with a neptunium tracer as a spike, such as 236gNp (t 1/2 = 1.5 × 105 y). Our research group has collected fundamental data for cross-sections of the 232Th + 7Li reaction products for use in spike production and chemical separation. In addition to the complete fusion reaction producing Np nuclides, incomplete fusion also occurs, especially in the reaction of 7Li, which splits into α and t and only a part of the projectile fuses with the target nucleus. In this study, the excitation functions of 234U, 233U, and 232U, produced by the incomplete fusion, were measured. The reaction mechanism is discussed by comparing the experimental values with those calculated using the EMPIRE code. In addition, we investigated the effect of incomplete fusion on the overall reaction.
Funding source: JSPS KAKENHI
Award Identifier / Grant number: 17H01874
Award Identifier / Grant number: 21H03609
Funding source: JSPS and the Austrian Science Fund
Award Identifier / Grant number: JPJSBP120202001
Funding source: Environmental Radioactivity Research Network Center
Award Identifier / Grant number: F-21-14
Award Identifier / Grant number: F-22-12
Funding source: JST FOREST program
Award Identifier / Grant number: JPMJFR231D
Acknowledgments
This work was performed at the RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo, Japan. The authors thank the crew of the RIKEN AVF cyclotron for accelerator operation. We are thankful to N. Otsuka of the International Atomic Energy Agency for help in providing the calculation using the EMPIRE code.
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Research ethics: Not applicable.
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Informed consent: Not applicable.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The authors state no conflict of interest.
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Research funding: This work was mainly supported by JSPS KAKENHI (grant number 17H01874 and 21H03609), Bilateral Joint Research Projects (grant Number JPJSBP120202001) supported by JSPS, and the Austrian Science Fund. It was also partially supported by the Environmental Radioactivity Research Network Center (accepted grant Numbers F-21-14 and F-22-12) and JST FOREST program, grant No. JPMJFR231D.
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Data availability: The datasets generated and/or analyzed during the current study except for supplementary data are available from the corresponding author on reasonable request.
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Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/ract-2025-0022).
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