Level densities in Fe-56,Fe-57 and Mo-96,Mo-97

Level densities up close to the neutron binding energy have been extracted from primary gamma spectra for Fe-56,Fe-57 and Mo-96,Mo-97 nuclei using (He-3,alphagamma) and (He-3,He-3 'gamma) reactions on Fe-57 and Mo-97 targets. It is shown that statistical spectroscopy provides a useful tool in this mass region. Apparent step structures in the level-density curves are tentatively explained by a schematic microscopic model comprising single-particle level spacings and seniority-conserving and seniority-nonconserving interactions.