Akademik Veri Yönetim Sistemi
PHYSICS OF ATOMIC NUCLEI, cilt.70, sa.9, ss.1634-1639, 2007 (SCI-Expanded)
Nuclear level densities and radiative strength functions (RSFs) in Fe-56 and Fe-57 were measured using the Fe-57(He-3, alpha gamma) and Fe-57(He-3, He-3'gamma) reactions, respectively, at the Oslo Cyclotron Laboratory. A low-energy enhancement in the RSF below 4-MeV energy was observed. This finding cannot be explained by common theoretical models. In a second experiment, two-step cascade intensities with soft primary transitions from the Fe-56(n, 2 gamma) reaction were measured. The agreement between the two experiments confirms the low-energy enhancement in the RSFs. In a third experiment, the neutron evaporation spectrum from the Mn-55(d, n)Fe-56 reaction was measured at 7-MeV deuteron energy at the John Edwards Accelerator Laboratory at Ohio University. Comparison of the level density of Fe-56 obtained from the first and third experiments gives an overall good agreement. Furthermore, observed enhancement for soft gamma rays is strengthened by the last experiment.