Special Features of Nuclear Reactions Induced by Loosely Bound Nuclei in the Vicinity of the Coulomb Barrier Height

Excitation functions are measured for complete-fusion and transfer reactions induced by the interaction of 6He and 6Li with 206Pb, 209Bi, and Pt. Data obtained for fusion reactions induced by 6He ions deviate from the predictions of the statistical model of compound-nucleus decay at projectile energies in the vicinity of the Coulomb barrier height. A strong enhancement of cross sections for fusion reactions induced by the interaction of 6He with target nuclei is observed. The cross sections for reactions of cluster transfer, neutron transfer from 6He, and deuteron transfer from 6Li at deep-subbarrier energies, are also found to be enhanced. These results are discussed from the point of view of the effect of the cluster structure of nuclei on the interaction probability at energies in the vicinity of the Coulomb barrier height.