(d,n) Reactions with 15-Mev Deuterons. II. Neutron Energy Spectra and Yields

Energy spectra of neutrons produced by bombarding several thick targets with 15-Mev deuterons were measured at various angles by observing proton recoils in photographic plates and in a triple coincidence-anticoincidence proportional counter telescope. The spectra measured in or near the forward direction strongly indicate a stripping rather than a compound nucleus interaction, while for those measured at large angles the opposite is the case. Analyses of the shapes of the spectra at low energy, and a study of the yields as a function of atomic number indicate that the stripping process is one in which the penetration of a coulomb barrier is important. This, together with an estimate of the relative cross sections for stripping and compound nucleus formation, also seems to favor a stripping process in which the proton is captured by nuclear forces rather than one in which the deuteron is broken up by electric forces.