A new empirical formula for calculation of (n,3n) cross sections of heavy mass nuclei in the energy region 22–27.5 MeV

In this paper we want to study (n,3n) reactions using an empirical formula derived on the basis of the statistical model considering reaction Q-value dependence. This formula was obtained by taking into account the exponential dependence on asymmetry parameter (N−Z)/A for neutron-induced reactions in Levkovskii's empirical formula. In addition, the present formula depends also on incident energy En, reaction Q-value and symmetry term (N−Z)2/A. Herein, a new analysis of experimental data of (n,3n) reactions in the energy region 22–27.5 MeV was carried out for quick estimation of cross sections of the heavy mass isotopes of odd Z-even N nuclides in the region of A = 151 to 209. We observed a good agreement of the experimental cross section data with the calculations performed using the present empirical formula. •An empirical formula for calculating the (n,3n) cross sections.•This formula was obtained by taking into account the exponential dependence on asymmetry parameter.•A new analysis of cross sections of (n,3n) reactions in the energy region 22–27.5 MeV.