SUBBARRIER FUSION INDUCED BY CL-35 AND CL-37 BEAMS ON MG-24,MG-25,MG-26 ISOTOPES

Sub-barrier fusion cross sections have been measured for the 35Cl+ 24,25,26Mg and 37Cl+ 24,25,26Mg reactions in the energy range 60 ≤ Elab ≤ 90 MeV, in steps of ΔE = 2 MeV. The in-beam γ-spectroscopy method has been employed to detect the evaporation residues. Care has been taken to eliminate the contamination due to 12C and 16O impurities of the targets or of the beams, and also the long lived γ-radioactivity induced by reactions. The fusion excitation functions exhibit rather large enhancement with respect to the barrier penetration model predictions. When this enhancement is analyzed in terms of the coupled-channel formalism, a sizeable contribution is accounted for by coupling the relative motion of the two interacting nuclei with the inelastic excitation modes of both target and projectile, (2+ and 3- states). However, at lower energies, the inelastic channel couplings still underpredict the experimental cross section values. © 1990.