Measurement Of Transport And Inelastic Scattering Cross Section For Fast Neutrons PDF Download

The time-of-flight technique was used with the ring scattering geometry in a laboratory with low neutron scattering background to measure the angular distributions of the cross sections for elastic and inelastic scattering of 14 MeV neutrons in natural chromium, iron, nickel, and niobium. Specifically for inelastic scattering included were: the 1.43 MeV and 4.56 MeV levels of 52Cr, the 0.85 MeV level, and (2.94-3.12) MeV and (4.46-4.51) MeV level groups of 56Fe, the 1.33 MeV level of 6°Ni combined with the 1.45 MeV level of 58Ni, and the 4.48 MeV level of 58Ni. Pulses of neutrons with time width of 0.9-1.1 ns were produced via the 3H(d, n)4He reaction in a 150 keV Cockcroft-Walton linear accelerator, with average intensities of 9x108 n/s. The energy of the incident neutrons was between 14.75 MeV (at 16°) and 13.48 MeV (at 160°). High purity scattering ring samples were used. The scattering angles ranged from (almost equal to)16° to (almost equal to)150°, for iron, chromium, and nickel, and from (almost equal to)16° to (almost equal to)160° for niobium, with a typical step of (almost equal to)10°. High purity ring samples were used.