High-precision prompt-γ-ray spectral data from the reaction Pu 241 (nth, f)

S. Oberstedt, R. Billnert, T. Belgya, T. Bryś, W. Geerts, C. Guerrero, F. J. Hambsch, Z. Kis, A. Moens, A. Oberstedt, G. Sibbens, L. Szentmiklosi, D. Vanleeuw, M. Vidali

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In this paper we present results from the first high-precision prompt-γ-ray spectral measurements from the reaction Pu241(nth, f). Apart from one recent experiment, no data are reported in the literature for this fissioning system, which motivated a new dedicated experiment. We have measured prompt-fission γ rays with three cerium-doped LaBr3 (two 5.08cm×5.08 cm and one 7.62cm×7.62 cm) and one CeBr3 (5.08cm×5.08 cm) scintillation detectors, which all exhibit excellent timing and good energy resolution. The average γ-ray multiplicity was determined to be ν̄γ=(8.21±0.09) per fission, the average energy to be εγ=(0.78±0.01) MeV, and the total energy to be Eγ,tot=(6.41±0.06) MeV as the weighted average from all detectors. Since the results from all detectors are in excellent agreement, and the total released γ energy is modestly higher than the one in the present evaluated nuclear data files, we suspect that the underestimation of the prompt-γ heating in nuclear reactors is due to fast-neutron-induced fission on U238 or rather from fission induced by γ rays from neutron capture in the construction material.

Original languageEnglish
Article number024618
JournalPhysical Review C - Nuclear Physics
Issue number2
Publication statusPublished - Aug 26 2014


ASJC Scopus subject areas

  • Nuclear and High Energy Physics

Cite this

Oberstedt, S., Billnert, R., Belgya, T., Bryś, T., Geerts, W., Guerrero, C., Hambsch, F. J., Kis, Z., Moens, A., Oberstedt, A., Sibbens, G., Szentmiklosi, L., Vanleeuw, D., & Vidali, M. (2014). High-precision prompt-γ-ray spectral data from the reaction Pu 241 (nth, f). Physical Review C - Nuclear Physics, 90(2), [024618]. https://doi.org/10.1103/PhysRevC.90.024618