Evidence of compound nucleus theory in the population of incompletely fused composite system ¹⁶⁰Dy

The fusion excitation functions of evaporation residues, populated through complete fusion and/or incomplete fusion, were measured in the O-18+Nd-146 system at an incident beam energy of approximate to 3-7 MeV/nucleon. These results were then compared with those obtained from the previously reported O-16+Nd-148 system. This comparison is particularly relevant since both systems lead to the population of the same compound nucleus, Er-164*, in the case of complete fusion, and the same intermediate composite system, Dy-160*, in the case of incomplete fusion. Significant enhancements in the measured excitation functions of evaporation residues populated via alpha-emitting channels indicate the population of such residues via incomplete fusion in addition to complete fusion. Further, a comparison of the measured data for O-18+Nd-146 and O-16+Nd-148 systems shows interesting results. The complete fusion and incomplete fusion cross-sections, reduced by three different procedures, are found to satisfactorily match each other, despite the major difference in the alpha- breakup threshold values of the projectiles O-18 (6.23 MeV) and O-16 (7.16 MeV). The effect of different alpha-breakup threshold values of the projectiles O-18 and O-16 was not observed in the comparison of incomplete fusion data for the systems O-18+Nd-146 and O-16+Nd-148. This may be attributed to the fact that the residues populated in the exit channel are emitted from the same intermediate composite system Dy-160* and also there is a high resemblance in the entrance channel mass asymmetry and other structural properties of these systems.