Neutron-induced gamma-ray production in 57Fe for incident neutron energies between 0.16 and 21 MeV

Interactions of neutrons with the iron isotope 57Fe have been studied by measuring gamma-ray production cross sections for incident neutron energies between 0.16 and 21 MeV. Neutrons produced by the Oak Ridge Electron Linear Accelerator impinged on a metallic iron sample enriched to 93% in the isotope 57Fe. The resulting gamma radiation was detected using a 100-cm3 Ge(Li) detector placed at 125 deg with respect to the neutron beam line. A complete description of the experiment is given. Absolute gamma-ray production cross sections were measured for gamma rays corresponding to the 57Fe(n,n1γ)57Fe, 57Fe(n,γ)58Fe, 57Fe(n,α54 Cr, 57Fe(n,2n)56Fe, and 57Fe(n,p)57Mn reactions. The cross section for the 57Fe(n,2n)56Fe reaction exceeds 1 b for E /SUB n/ about 15 MeV, and the cross section for the 57Fe(n,p)57Mn reaction exceeds 0.2 b for E /SUB n/ about 9 MeV. A new excited state is postulated account for observed data. Several new transitions are reported for decay of levels in 57Fe. Measured cross sections are compared with data obtained from the current ENDF/B evaluation