Energy dependence of the isomeric cross section ratio in the Ni-58(n,p)Co-58(m,g) reactions - art. no. 017602

Excitation functions of the Ni-58(n,p) Co-58(m,g) reactions were measured i n 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 me asured data. The shape and magnitude of the R(E-n) function are described b y model calculations using a consistent parameter set. Questions of the inp ut level scheme were solved based on the accurate isomeric ratio measured a t 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 multipolarity. [S0556- 2813(99)02207-4].