Energy dependence of the isomeric cross section ratio in $\mathrm{the}{\hspace{0.5em}}^{58}\mathrm{Ni}{\mathrm{}(n,p)\mathrm{}}^{58}{\mathrm{Co}}^{m,g}$ reactions

Excitation functions of the ${}^{58}\mathrm{Ni}{\mathrm{}(n,p)\mathrm{}}^{58}{\mathrm{Co}}^{m,g}$ reactions were measured in the energy range from 2 to 15 MeV. The energy dependence of the isomeric cross-section ratio $R={\sigma }_m/({\sigma }_m+{\sigma }_g)$ is deduced from the measured data. The shape and magnitude of the ${R(E}_n)$ function are described by model calculations using a consistent parameter set. Questions of the input level scheme were solved based on the accurate isomeric ratio measured at low energy region. The measured R-value prefers the mixing ratio value of $-2.3$ for the transition of the 52.8 keV state to the 24.9 keV state, over the $-0.33$ value. The transition has predominantly $E2\mathrm{}$ multipolarity.