The investigation of the neutron emission spectra of 232Th and 238U for neutron incident energy from 2 to 18 MeV

In this study, experimental neutron-emission spectra produced by (n, xn) reactions on nuclei 232Th have been compared with experimental 238U(n, xn) neutron-emission spectra from 2 to 18 MeV. Angle-integrated cross-sections in neutron induced reactions on targets 238U have been calculated at the bombarding energies from 2 to 18 MeV. In the calculations, the geometry dependent hybrid model and the cascade exciton model including the effects of pre-equilibrium have been used. In addition, we have described how multiple pre-equilibrium emissions can be included in the Feshbach–Kerman-Koonin (FKK) fully quantum-mechanical theory. By analyzing (n, xn) reaction on 238U with the incident energy from 2 to 18 MeV, the importance of multiple pre-equilibrium emission can be seen clearly. All calculated results have been compared with experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.