GRS: A statistical and non-statistical model code for calculations of cross sections and gamma-ray spectra

This paper briefs the non-statistical processes in neutron radiative capture reactions such as potential-valence captures, direct-semidirect captures, and captures in the compound elastic and inelastic channels, their physical significances and calculational expressions. Then a code GRS to calculate gamma-ray production data resulting from neutron induced reactions as well as relevant cross sections is described. In addition to multistep Hauser-Feshbach model, special attention has been paid to the calculation of higher energy gamma-rays, mainly produced by the non-statistical processes.