Fission fragment yield distribution in the heavy-mass region from the ²³⁹Pu(n_th,f) reaction

Y.K. Gupta , D.C. Biswas , O. Serot (1) , D. Bernard (1) , O. Litaize (1) , S. Julien-Laferrière (2) , A. Chebboubi (2) , G. Kessedjian (2) , C. Sage (2) , A. Blanc (3) , H. Faust (3) , U. Köster (3) , A. Ebran (4) , L. Mathieu (5) , A. Letourneau (6) , T. Materna (6) , S. Panebianco (6)

1 CEA Cadarache
2 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
3 ILL - Institut Laue-Langevin
4 DAM - Direction des Applications Militaires
5 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
6 CEA - Commissariat à l'énergie atomique et aux énergies alternatives

The fission fragment yield distribution has been measured in the Pu239nth,f reaction in the mass region of A=126 to 150 using the Lohengrin recoil-mass spectrometer. Three independent experimental campaigns were performed, allowing a significant reduction of the uncertainties compared to evaluated nuclear data libraries. The long-standing discrepancy of around 10% for the relative yield of A=134 reported in JEF-2.2 and JEFF-3.1.1 data libraries is finally solved. Moreover, the measured mass distribution in thermal neutron-induced fission does not show any significant dip around the shell closure (A=136) as seen in heavy-ion fission data of Pb208(O18, f) and U238(O18, f) reactions. Lastly, comparisons between our experimental data and the predictions from Monte Carlo codes (gef and fifrelin) are presented and discussed.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

Y.K. Gupta, D.C. Biswas, O. Serot, D. Bernard, O. Litaize, et al.. Fission fragment yield distribution in the heavy-mass region from the ²³⁹Pu(n_th,f) reaction. Physical Review C, 2017, 96 (1), pp.014608. ⟨10.1103/PhysRevC.96.014608⟩. ⟨hal-01582780⟩