Semi-empirical systematics of (n, 2n), (n, α) reactions cross sections at 14-15 MeV neutron energy

In this study we propose new semi-empirical formulas by modifying the formula of Levkovskii with the new parameters for ( n, 2n) and ( n, alpha) reactions cross-sections at 14 - 15 MeV neutron incident energy. The cross sections have been calculated using the asymmetry parameter depending on empirical formulas for the incoming energies of 14 - 15 MeV neutrons. The parameters obtained by modifying the original formula of Levkovskii and Konno et al. have been determined by applying the least squares. fitting method to the experimental cross sections, and the systematics of the ( n, 2n) and ( n, a) reactions have been studied. We have also suggested different parameters for the empirical formula to reproduce the cross sections of the ( n, 2n) and ( n, alpha) reactions for the neutron incident energy of 14 - 15 MeV. The modified formulas yielded cross sections representing markedly smaller chi-square (chi(2)) deviations from experimental values, and values much closer to units as compared with those calculated using Levkovskii's and Konno et al. original formulas. The results obtained have been discussed and compared with the other empirical formulas, and found to be well in agreement when used to correlate the available experimental sigma( n, 2n) and s( n, sigma) data of different nuclei.