Experimental investigation of the effect of entrance channel parameters on incomplete fusion: a complete study of the ¹²C+¹⁵⁹Tb system

Complete and incomplete fusion cross sections of the reaction residues populated in the C-12+Tb-159 system have been measured at above-barrier energies, using activation technique . The experimentally measured cross sections were also compared to the statistical model code PACE4. The experimental excitation functions of the non-alpha emitting channels show a good agreement with theoretical predictions, whereas an enhancement for alpha emitting channels has been observed over the PACE4 predictions. The present study involves an assessing of fusion incompleteness in the C-12+Tb-159 reaction by comparing the fusion excitation function with coupled channels calculations and the extracted fusion function with the universal fusion function. The experimentally measured complete fusion cross sections for C-12+Tb-159 system are found to be suppressed by 10% in comparison to the theoretical predictions . The large cross sections measured for incomplete fusion products confirm the interpretation that this suppression of fusion results from breakup of C-12 projectile with the target nucleus. The present results have also been compared with those obtained for the interaction of C-13, O-16, and O-18 projectiles with the same target 159Tb, where role of strong projectile structure has been found. This correlates the dependence of incomplete fusion reaction process with the projectile Q(alpha) value. It is also observed that incomplete fusion process depends on the mass asymmetry and Coulomb factor of interacting partners. The influence of incomplete fusion dynamics on target structure has been explained on the basis of target deformation parameter. Further, the neutron excess parameter exposes the role of ICF on the structure of projectile along with that of the target.