Neutron Inelastic Scattering in Silicon-28 to 4.15 MeV

The absolute 125-deg differential gamma-ray production cross section for the 1780-keV transition in the ²⁸Si(n,n′γ)²⁸Si reaction has been measured from 1.96- to 4.15-MeV bombarding energy. This transition represents the decay of the 2+ first excited state to the 0⁺ ground state of ²⁸Si. The data were corrected for neutron multiple scattering as well as neutron and gamma-ray attenuation in the sample. The angle-integrated neutron scattering cross section was inferred from the gamma-ray production data using the shape of the gamma-ray angular distributions obtained from compound nucleus statistical model calculations. Incident neutrons were produced via the ³H(p,n)³ He reaction using a target ∼100 keV thick for 3.5-MeV protons, and this energy spread is reflected in the structure observed in the cross section.