The excitation functions for production of nineteen isotopes of At, Po, Bi, Pb, and Tl in the interaction of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ with ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$ between 57 and 97 MeV incident energy have been measured with the activation technique. The analysis of these data allows one to estimate the cross sections for complete fusion of ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and incomplete fusion of ${}_{}{}^8{}_{}{}^{}\mathrm{Be}$ and α fragments with gold, and shows the presence of preequilibrium emissions at incident energies only slightly higher than the Coulomb barrier acting between ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$.

• Received 19 May 1993

DOI:https://doi.org/10.1103/PhysRevC.48.1815