The calculation of neutron transport in air requires an accurate knowledge of the neutron cross sections for nitrogen and oxygen. Existing direct measurement of the total elastic cross section for nitrogen is in marked disagreement with the value deduced by taking the difference between the total cross section and the sum of all partial non-elastic cross sections. This discrepancy in the available data indicates an error in the total-elastic measurement of 30% or in the total non-elastic cross section of 50%. A technique to measure differential cross sections for the small-angle (3 degrees to 15 degrees) scattering of fast neutrons has been developed and applied to a study of the scattering of 7.55 and 9.5 MeV neutrons from N, O, and C. Preliminary analysis of measurements obtained thus far show that the forward angle elastic scattering in nitrogen (theta

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.