Gamow-Teller strength inNi60,62,64(n,p) reactions at 198 MeV

Measurements of the (n,p) reaction cross section on ${}_{}{}^{60,62,64}{}_{}{}^{}\mathrm{Ni}$ have been made at 198 MeV for ${\mathrm{\theta }}_{\mathrm{lab}}$=0–20° in 4° steps. Multipole analyses have been performed on the resulting spectra and Gamow-Teller (GT) strength distributions have been obtained. These GT distributions have been found to occur as strong peaks at low excitation energy in the final Co nuclei and extend weakly upwards to 30 MeV of excitation. Comparisons of the data with renormalized shell-model calculations show reasonable agreement at low excitation, though the calculations predict very little strength at excitation energies above about 6 MeV.