Alpha particles from the dissociation of ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ and ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ on Al and Au targets have been observed at 5° in the laboratory for beam energies near 65 MeV/nucleon. Coincident γ rays were observed by an array of ${\mathrm{BaF}}_2$ scintillators that surrounded the target, subtending 90% of the solid angle. In all cases at least half of the observed events were accompanied by γ rays, presumably from excitation of the target via nuclear processes. For ${}_{}{}^6{}_{}{}^{}\mathrm{He}$ incident on the Au target, the data permit an approximate separation into nuclear and Coulomb processes; the latter are in qualitative agreement with theoretical predictions.

• Received 17 November 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.2355