The differential ranges of ${}_{}{}^{64}{}_{}{}^{}\mathrm{Cu}$ recoils emitted at 0-12° and 35-46° to the beam were measured for the ${}_{}{}^{65}{}_{}{}^{}\mathrm{Cu}({}_{}{}^3{}_{}{}^{}\mathrm{He},\alpha )$ reaction at 32 MeV by means of the electrostatic-collection technique. The results have been compared with a Monte Carlo evaporation calculation, as well as with a kinematic calculation for $\alpha$-particle emission ascribable to a pickup process. The range at 0-12° is consistent with the evaporation of four single nucleons, and the contribution from pickup is less than 2%. The differential range at 35-46° consists of two well-resolved peaks whose positions are in accord with the expectations for these two mechanisms. The pickup process is found to account for (12±2)% of the recoils emitted at this angle.

• Received 8 June 1971

DOI:https://doi.org/10.1103/PhysRevC.5.1247