The scattering of neutrons and of protons by deuterons

The theoretical treatment of neutron-deuteron collisions in an earlier paper (Buckingham & Massey 1941) is here extended to include neutrons with energy up to 16 MeV, and also collisions between deuterons and protons with incident energy up to 11·5 MeV. Previous results are also modified by the inclusion of effects arising from a relative angular momentum √6ћ (d scattering). A detailed comparison is made with experimental evidence for the total elastic crosssection for n-d collisions, and for the angular distribution of protons and neutrons scattered by deuterons. Within the accuracy of measurement the evidence is consistent with charge independence of the nuclear forces at the energies concerned; the comparison with calculated results appears strongly to favour forces of the symmetrical exchange type (or some similar exchange type) as against ordinary forces. Iterative methods of solving numerically the integro-differential equations arising in this kind of problem are discussed in an appendix.