Impact of gamma-decay description on nuclear reaction characteristics

Abstract

The results of the study of gamma-transition description in fast neutron capture and photofission are presented. Recent experimental data were used, namely, the spectrum of prompt gamma-rays in the energy range 2÷18 MeV from 14-MeV neutron capture in natural Ni and isomeric ratios in primary fragments of photofission of the isotopes of U, Np and Pu by bremsstrahlung with end-point energies e E =10.5, 12 and 18 MeV. The data are compared with the theoretical calculations performed within EMPIRE 3.2 and TALYS 1.6 codes. The mean value of angular momenta and their distributions were determined in the primary fragments 84 Br, 97 Nb, 90 Rb, 131,133 Te, 132 Sb, 132,134 I, 135 Xe of photofission. An impact of the characteristics of nuclear excited states on the calculation results is studied using different models for photon strength function and nuclear level density.