Neutron-induced fission cross section of U-234 measured at the CERN n_TOF facility

D. Karadimos , L. Audouin (1) , S. David (1) , S. Isaev (1) , C. Stephan (1) , L. Tassan-Got (1) , L. Ferrant (1) , G. Aerts (2) , S. Andriamonje (2) , E. Berthoumieux (2) , W. Dridi (2) , F. Gunsing (2) , J. Pancin (2) , L. Perrot (2) , A. Plukis (2) , P. Baumann (3) , M. Kerveno (3) , S. Lukic (3) , G. Rudolf (3) , P. Pavlopoulos (4) , B. Haas (5)

1 IPNO - Institut de Physique Nucléaire d'Orsay
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
3 IReS - Institut de Recherches Subatomiques
4 Pôle Universitaire Léonard de Vinci
5 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan

The neutron-induced fission cross section of 234 U has been measured at the CERN n_TOF facility relative to the standard fission cross section of 235 U from 20 keV to 1.4 MeV and of 238 U from 1.4 to 200 MeV. A fast ionization chamber (FIC) was used as a fission fragment detector with a detection efficiency of no less than 97%. The high instantaneous flux and the low background characterizing the n_TOF facility resulted in wide-energy-range data (0.02 to 200 MeV), with high energy resolution, high statistics, and systematic uncertainties bellow 3%. Previous investigations around the energy of the fission threshold revealed structures attributed to β -vibrational levels, which have been confirmed by the present measurements. Theoretical calculations have been performed, employing the TA LY S code with model parameters tuned to fairly reproduce the experimental data.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

D. Karadimos, L. Audouin, S. David, S. Isaev, C. Stephan, et al.. Neutron-induced fission cross section of U-234 measured at the CERN n_TOF facility. Physical Review C, 2014, 89, pp.044606. ⟨10.1103/PhysRevC.89.044606⟩. ⟨in2p3-01073786⟩