Spectrum of High-Energy Gamma Rays Following Thermal-Neutron Capture by Er166

The thermal-capture γ-ray spectrum of the Er166(n, γ)Er167 reaction in a sample enriched in Er166(99.97%) has been studied with a Ge(Li) pulse-height spectrometer. Some of the transitions are interpreted as populating states having excitation energies in good agreement with those of known states, and several additional levels with excitation energies less than 2 MeV are tentatively assigned on the basis of the data. The distribution of the …