Effects of the nuclear structure of fission fragments on the high-energy prompt fission γ -ray spectrum in U 235 (nth,f)
(2019) In Physical Review C 100(4).- Abstract
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... (More)
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.
(Less)
- author
- organization
- publishing date
- 2019
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review C
- volume
- 100
- issue
- 4
- article number
- 044610
- publisher
- American Physical Society
- external identifiers
-
- scopus:85073833389
- ISSN
- 2469-9985
- DOI
- 10.1103/PhysRevC.100.044610
- language
- English
- LU publication?
- yes
- id
- 33633ca6-4ef1-4b97-8d42-976265056d75
- date added to LUP
- 2019-11-04 12:18:21
- date last changed
- 2022-04-18 18:35:24
@article{33633ca6-4ef1-4b97-8d42-976265056d75, abstract = {{<p>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.</p>}}, author = {{Makii, H. and Nishio, K. and Hirose, K. and Orlandi, R. and Léguillon, R. and Ogawa, T. and Soldner, T. and Köster, U. and Pollitt, A. and Hambsch, F. J. and Tsekhanovich, I. and Aïche, M. and Czajkowski, S. and Mathieu, L. and Petrache, C. M. and Astier, A. and Guo, S. and Ohtsuki, T. and Sekimoto, S. and Takamiya, K. and Frost, R. J.W. and Kawano, T.}}, issn = {{2469-9985}}, language = {{eng}}, number = {{4}}, publisher = {{American Physical Society}}, series = {{Physical Review C}}, title = {{Effects of the nuclear structure of fission fragments on the high-energy prompt fission γ -ray spectrum in U 235 (nth,f)}}, url = {{http://dx.doi.org/10.1103/PhysRevC.100.044610}}, doi = {{10.1103/PhysRevC.100.044610}}, volume = {{100}}, year = {{2019}}, }