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 E, reaction Q-value and symmetry term (N-Z)/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.