1. Prompt fission γ -ray data from spontaneous fission and the mechanism of fission-fragment de-excitation.
- Author
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Oberstedt, Stephan, Dragic, Aleksandar, Gatera, Angelique, Göök, Alf, Hambsch, Franz-Josef, and Oberstedt, Andreas
- Subjects
SPONTANEOUS fission ,GAMMA rays ,NUCLEAR fission ,NUCLEAR reactor cores ,PROMPT neutrons ,NEUTRON multiplicity - Abstract
The investigation of prompt γ -ray emission in nuclear fission has a great relevance for the assessment of prompt heat generation in a reactor core and for the better understanding of the de-excitation mechanism of fission fragments. Some years ago experimental data was scarce and available only from a few fission reactions,
233,235 U(nth , f),239 Pu(nth , f), and252 Cf(sf). Initiated by a high priority data request published by the OECD/NEA a dedicated prompt fission γ -ray measurement program is being conducted at the Joint Research Centre Geel. In recent years we obtained new and accurate prompt fission γ -ray spectrum (PFGS) characteristics (average number of photons per fission, average total energy per fission and mean photon energy) from252 Cf(sf),235 U(nth, f) and239,241 Pu(nth, f) within 2% of uncertainty. In order to understand the dependence of prompt fission γ -ray emission on the compound nuclear mass and excitation energy, we started a first measurement campaign on spontaneously fissioning plutonium and curium isotopes. Results on PFGS characteristics from240,242 Pu(sf) show a dependence on the fragment mass distribution rather than on the average prompt neutron multiplicity, pointing to a more complex competition between prompt fission γ -ray and neutron emission. [ABSTRACT FROM AUTHOR]- Published
- 2017
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