Differentialn−pScattering Cross Section for 220-Mev Neutrons

The differential neutron-proton scattering cross section as a function of angle has been investigated for neutron energies of 220 Mev and 180 Mev. A ½-inch Be target at the 58¼-inch radius in the University of Rochester 130-in. cyclotron was used to produce a beam of neutrons. This neutron beam scattered protons from a polyethylene scatterer which were detected by a four scintillation counter coincidence telescope. A measurement of the pulse height from the last counter was used to determine the energy of the scattered proton. The effect of the carbon in the polyethylene was subtracted by taking runs with a carbon scatterer calculated to have the same number of carbon atoms per ${\mathrm{cm}}^2$ as had the polyethylene. Runs were taken from 0° to 50° for the proton angle in the laboratory coordinate system. A comparison is made of the 220-Mev angular distribution with the Berkeley 260-Mev data which indicates essential agreement of the shapes.