The 54,56Fe(n,p)54,56Mn reactions at En = 97 MeV

Double-differential cross sections of the 54,56Fe(n, p) reactions have been measured at 97 MeV in the angular range 0-30 for excitation energies up to 40 MeV. The spectra have been decomposed into different multipolarities by a technique based on the use of sample angular distributions calculated within the distorted-wave Born approximation. From the identified Gamow-Teller strength, Ssub(β+) values were obtained for 54Fe and 56Fe. Comparisons with available shell-model calculations of the GT strength were made. The results are important for models of supernova explosions since electron-capture rates, which are proportional to Ssub(β+), in 1f2p-shell nuclei affect the dynamics of the star. At higher excitation energies, the spectra are dominated by L=1 strength in broad distributions with a maximum at about 12 MeV. Microscopic calculations based on the random-phase approximation were performed and compared with the experimental data. (orig.)