Calculation of excitation functions and isomeric cross section ratio of the58Ni(n,p)58Com,greactions in the 1–20 MeV energy range

Calculation of the excitation functions and isomeric cross section ratio of ${}^{58}\mathrm{Ni}{\mathrm{}(n,p)\mathrm{}}^{58}{\mathrm{Co}}^{m,g}$ reactions has been carried out using Hauser-Feshbach and preequilibrium nuclear reaction model codes in the 1–20 MeV energy range, and compared with measurements and previous calculations. The structure in the isomeric cross section ratio curve in the low-energy region has been investigated. The anomaly of the branching ratio of the 53 keV ${(4\mathrm{}}^{+})$ state to the isomeric states has been resolved by using more precise formalism of the $\gamma$-ray transition probabilities available in the literature for the continuum and discrete levels.