Effects of nuclear deformation on fusion probability in the reactions of82Se+natCeand76Ge+150Ndnear the Coulomb barrier

Abstract

Evaporation residue (ER) cross sections for ${}^{82}\mathrm{Se}{+}^{\mathrm{nat}}\mathrm{Ce}{(Z}_{1}{Z}_{2}=1972)$ were measured in the vicinity of the Coulomb barrier and the fusion probability was obtained with the aid of calculated survival probability. This fusion probability was compared with that for ${}^{76}\mathrm{Ge}{+}^{150}\mathrm{Nd}{(Z}_{1}{Z}_{2}=1920),$ which was determined with the same manner by using the data published by us. The former system represents fusion of two spherical nuclei, the latter fusion involving the prolately deformed target ${}^{150}\mathrm{Nd}.$ The collision of ${}^{76}\mathrm{Ge}$ with the side of ${}^{150}\mathrm{Nd}$ is the most compact configuration at touching. The system ${}^{82}\mathrm{Se}{+}^{\mathrm{nat}}\mathrm{Ce}$ showed fusion hindrance in the form of extra-extra-push energy of $27\ifmmode\pm\else\textpm\fi{}5\mathrm{MeV},$ whereas the system ${}^{76}\mathrm{Ge}{+}^{150}\mathrm{Nd}$ does not show fusion hindrance at and above the Coulomb barrier energy, suggesting that the reaction starting from the compact touching point results in a higher fusion probability.