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

Excitation functions of the ${}^{58}$Ni$(n,p{)}^{58}$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.