Neutron scattering and models: iron

Differential elastic and inelastic neutron-scattering cross sections of elemental iron are measured from 4.5 to 10 MeV in increments of ≈ 0.5 MeV. The measurements are made at ≳ 40 scattering angles distributed between ≈ 17° and 160°, with emphasis on elastic scattering and inelastic scattering due to excitation of the yrast 2 ⁺ state. The measured data is combined with earlier lower-energy results from this laboratory, with recent high-precision ≈ 9.5-15 MeV results from the Physikalisch. Technische Bundesanstalt and with selected values from the literature to provide a detailed neutron-scattering data base extending from ≈ 1.5 to 26 MeV. This data is interpreted in the context of spherical-optical and coupled-channels (vibrational and rotational) models, and the physical implications are discussed. Deformation, coupling, asymmetry and dispersive effects are explored. A good description of the interaction of neutrons with iron is achieved over the energy range ≲ 1.5-26 MeV, avoiding the dichotomy between high- and low-energy interpretations found in previous work in this mass region.