Nuclear energy levels of ${\mathrm{Fe}}^{56}$ and ${\mathrm{Co}}^{59}$ have been determined by analyses of particles from the ${\mathrm{Co}}^{59}(p, \alpha )$, ${\mathrm{Fe}}^{56}(p, p^{\prime })$, and ${\mathrm{Co}}^{59}(p, p^{\prime })$ reactions with a broad-range single-gap magnetic spectrograph. In the first 6.7 MeV of excitation energy, 100 levels of ${\mathrm{Fe}}^{56}$, and in the first 4.0 MeV, 62 levels of ${\mathrm{Co}}^{59}$ were resolved and investigated. In the excitation-energy region of ${\mathrm{Fe}}^{56}$ examined previously, new levels were found at 3.748 and 4.802 MeV and the previously reported level at 4.676 MeV was resolved into a doublet with energies of 4.675 and 4.688 MeV. Information on the spins of a few levels of ${\mathrm{Fe}}^{56}$ is obtained from their cross sections in the aforementioned reactions. The energy dependence of the level density is found to agree qualitatively with theoretical expectations for a finite superconducting nucleus.

• Received 1 September 1965

DOI:https://doi.org/10.1103/PhysRev.141.1053