Excitation function and isomeric cross-section ratio for the 61Ni(p,α)58Com,g process

Excitation functions were measured by the stacked-foil technique for 61Ni(p,α)58Com and 61Ni(p,α)58Com+g reactions using 88.84% enriched 61Ni from threshold up to 18.6 MeV. Thin samples of 61Ni were prepared by electrodeposition on gold foils. The radioactivity of the activation products was determined via high resolution x- and γ-ray spectrometry. From the measured experimental data isomeric cross-section ratios [σm/σm+g] were deduced. Statistical model calculations taking into account precompound effects were performed for the strong 61Ni(p,xn) channels as well as for the weak 61Ni(p,α) process. The experimental 61Ni(p,xn) and 61Ni(p,α) excitation functions are described well by the calculation over the whole investigated energy range. The isomeric cross-section ratio for the isomeric pair 58Com,g formed in the 61Ni(p,α) process is also reproduced well by the model calculation, provided the input level scheme and the spin distribution are properly taken into account