Gamma-Ray Production Cross Sections for Iron and Aluminum

The Linac time-of-flight technique has been used to measure the differential gamma-ray production cross sections for neutron interactions with natural Fe and Al in the neutron energy range 0.9 to 17 MeV. Ring-shaped scattering samples were placed at the terminus of a 51-meter neutron flight path at the Gulf Radiation Technology Linac facility. The gamma rays from (n,x gamma) reactions were detected with an 80-cc Ge(Li) detector placed on the centerline of the flight path so as to observe gamma rays emitted from the samples at an angle of about 125 degrees with respect to the incident neutron beam. This angle minimized the effect of gamma-ray anisotropy on the determination of the angle-integrated cross section. (Author)