Excitation function of the 93Nb(n,2n)92Nbm reaction from threshold to 24 MeV

The cross sections for formation of Nb-92(m) in the Nb-93(n,2n)Nb-92(m) reaction induced by 9 to 24 MeV neutrons have been theoretically estimated using the TALYS-1.0 computer program. The variations of the cross sections with the level densities and effective imaginary potential were also studied to obtain the best fit of the excitation function. It is observed that the theoretical cross sections match fairly well with the experimental cross sections reported in literature only when both contributions from negative and positive parity levels of Nb-92 are considered. The results of the present study reveal that the approach of the earlier worker to neglect the contributions of the low-lying negative parity energy levels in the formation of Nb-92(m), in order to match the theoretical cross sections with the experimental cross sections cannot be an obvious solution, particularly when the gamma rays emitted by Nb-92 nuclei in the transition from negative parity levels have been measured.