Effects of the nuclear structure of fission fragments on the high-energy prompt fission γ -ray spectrum in U235(nth,f)
| Autor: | Andrew Pollitt, Song Guo, Tsutomu Ohtsuki, Katsuhisa Nishio, T. Soldner, R. Leguillon, S. Czajkowski, A. Astier, R. Orlandi, L. Mathieu, Kentaro Hirose, Hiroyuki Makii, R. J. W. Frost, M. Aiche, C. M. Petrache, I. Tsekhanovich, F.-J. Hambsch, Ulli Köster, Toshihiko Kawano, T. Ogawa, Shun Sekimoto, Koichi Takamiya |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Physics
Nuclear reaction Range (particle radiation) 010308 nuclear & particles physics Fission Astrophysics::High Energy Astrophysical Phenomena Spectrum (functional analysis) Nuclear structure 7. Clean energy 01 natural sciences Spectral line Nuclear physics 0103 physical sciences Nuclide Nuclear Experiment 010306 general physics Excitation |
| Zdroj: | Physical Review C. 100 |
| ISSN: | 2469-9993 2469-9985 |
| Popis: | The prompt fission γ-ray energy spectrum for cold-neutron-induced fission of U235 was measured in the energy range Eγ=0.8–20MeV, by gaining a factor of about 105 in statistics compared to the measurements performed so far. The spectrum exhibits local bump structures at Eγ≈4MeV and ≈6MeV, and also a broad one at ≈15MeV. In order to understand the origins of these bumps, the γ-ray spectra were calculated using a statistical Hauser-Feshbach model, taking into account the deexcitation of all the possible primary fission fragments. It is shown that the bump at ≈4MeV is created by the transitions between the discrete levels in the fragments around Sn132, and the bump at ≈6MeV mostly comes from the complementary light fragments. It is also indicated that a limited number of nuclides, which have high-spin states at low excitation energies, can contribute to the bump structure around Eγ≈15MeV, induced by the transition feeding into the low-lying high-spin states. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|