The angular distribution of ${\mathrm{Cu}}^{64}$ nuclei produced in the interaction of ${\mathrm{He}}^3$ ions with ${\mathrm{Cu}}^{65}$ has been measured over the energy range 12-32 MeV. The results have been compared with a distroted-wave calculation for the (${\mathrm{He}}^3,\alpha$) pickup process and with a statistical-theory calculation for the evaporation process. It is found that contributions from both mechanisms are required to reproduce the data. The compound-nuclear process, which involves the evaporation of an $\alpha$ particle at the lower energies and of four nucleons at the higher ones, accounts for most of the ${\mathrm{Cu}}^{64}$ yield at small angles to the beam, whereas the pickup process accounts for most of it at large angles.

• Received 4 December 1967

DOI:https://doi.org/10.1103/PhysRev.170.958