The Scattering of High Energy Neutrons by Protons

The scattering has been calculated, using the exact formula, for neutron energies between 20 and 80 Mev, with ranges of 2.0 and 2.8×{}10^-13 cm for the nuclear force and using ordinary, exchange, and symmetric forces. The maximum of the scattered intensity at 180^∘{} is sensitive to the range of the forces; experiments with neutrons from 30 to 60 Mev would permit a rather conclusive determination of the range. The total cross section for forces of the exchange type is much smaller than that obtained from the Born approximation, even at 80 Mev.