Neutron-induced fission cross section of Np 237 in the keV to MeV range at the CERN n-TOF facility

Abstract

The neutron-induced fission cross section of Np237 was experimentally determined at the high-resolution and high-intensity facility n-TOF, at CERN, in the energy range 100 keV to 9 MeV, using the U235(n,f) and U238(n,f) cross section standards below and above 2 MeV, respectively. A fast ionization chamber was used in order to detect the fission fragments from the reactions and the targets were characterized as far as their mass and homogeneity are concerned by means of α spectroscopy and Rutherford backscattering spectroscopy respectively. Theoretical calculations within the Hauser-Feshbach formalism have been performed, employing the empire code, and the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels.