Late-time emission of prompt fission rays
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
The emission of prompt fission γ rays within a few nanoseconds to a few microseconds following the scission point is studied in the Hauser-Feshbach formalism applied to the deexcitation of primary excited fission fragments. Neutron and γ-ray evaporations from fully accelerated fission fragments are calculated in competition at each stage of the decay, and the role of isomers in the fission products, before β decay, is analyzed. The time evolution of the average total γ-ray energy, the average total γ-ray multiplicity, and the fragment-specific γ-ray spectra is presented in the case of neutron-induced fission reactions of 235U and 239Pu, as well as spontaneous fission of 252Cf. The production of specific isomeric states is calculated and compared to available experimental data. About 7% of all prompt fission γ rays are predicted to be emitted between 10 ns and 5 μs following fission, in the case of 235U and 239Pu(nth,f) reactions, and up to 3% in the case of 252Cf spontaneous fission. The cumulative average total γ-ray energy increases by 2% to 5% in the same time interval. Lastly, those results are shown to be robust against significant changes in the model input parameters.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
- Grant/Contract Number:
- AC52-06NA25396
- OSTI ID:
- 1343702
- Alternate ID(s):
- OSTI ID: 1337442
- Report Number(s):
- LA-UR-16-24045; PRVCAN; TRN: US1701102
- Journal Information:
- Physical Review C, Vol. 94, Issue 6; ISSN 2469-9985
- Publisher:
- APSCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Review on the progress in nuclear fission—experimental methods and theoretical descriptions
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Correlated prompt fission data in transport simulations
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journal | January 2018 |
Correlated Prompt Fission Data in Transport Simulations | text | January 2017 |
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