56Fe(p,nγ)56Co coincidence experiments at several beam energies

Levels of Co⁵⁶ up to 2.6 MeV of excitation have been studied by Fe⁵⁶(p,nγ) coincidence experiments. γ rays were detected with a 40-cm³ coaxial Ge(Li) detector. Neutrons were detected with a 1000-cm³ liquid scintillation counter. Pulse-shape discrimination was used to distinguish neutrons from the γ-ray contamination in the neutron detector. Energy and time-of-flight information was stored for each coincident event on magnetic tape with 1024×256-channel resolution. Gated one-dimensional γ spectra were also taken with 4096-channel resolution in order to obtain accurate energies (±0.5 keV). Proton beam energies of 7.7, 8.1, 8.5, 9.5, and 10 MeV were used to determine the approximate threshold for the appearance of the individual γ rays. 21 Co⁵⁶ γ rays were identified. The decay scheme constructed is consistent with the known information on this nucleus and supports a number of spin assignments recently suggested by Schneider and Daehnick. The experimental procedure is discussed in some detail.