Co59(p, α)Fe56 and Fe56(p, p′) Reactions

Abstract

Evaporation spectra of $\alpha$ particles from the ${\mathrm{Co}}^{59}(p, \alpha ){\mathrm{Fe}}^{56}$ reaction and protons from the ${\mathrm{Fe}}^{56}(p, p^{\prime })$ reaction were investigated with silicon surface-barrier detectors for proton-bombarding energies of 9 to 13.5 MeV. The $\alpha$-particle spectra are in good agreement with previous results. However, the proton spectra differ somewhat from earlier measurements. The anisotropy of the $\alpha$ particles from the ${\mathrm{Co}}^{59}(p, \alpha )$ reaction was measured as a function of $\alpha$-particle energy for proton-bombarding energies of 9 to 13.5 MeV. The level density and the spin-cutoff factor $\sigma$ were calculated from the experimental results as a function of excitation energy in the range 3 to 9 MeV. The level density varies irregularly with excitation energy at the lower excitation energies and increases smoothly in an exponential manner at higher excitation energies. The nuclear temperature is in the range of 1.10 to 1.45 MeV and appears to increase slightly with excitation energy. The spin-cutoff factor $\sigma$ increases from ${3.5}_{-0.3\mathrm{}}^{+0.6\mathrm{}}$ to ${3.8}_{-0.3\mathrm{}}^{+0.5\mathrm{}}$ in the excitation-energy range of 4 to 8 MeV.