The Scattering of 2.5-Mev Neutrons in Helium

From the observations of Barschall and Kanner on the scattering of 2.5-Mev neutrons in helium is deduced the existence at this energy of a coupling between the spin and orbital motion of the neutron. Less clear-cut evidence points to appreciable interaction between a neutron and alpha-particle of two units of mutual angular momentum, the classical distance of closest approach of which would be 7×${10}^{-13\mathrm{}}$ cm.