Breakup and n -transfer effects on the fusion reactions Li6,7+Sn120,119 around the Coulomb barrier

Abstract

This paper presents values of complete fusion cross sections deduced from activation measurements for the reactions $\phantom{\rule{0.16em}{0ex}}^{6}\mathrm{Li}+\phantom{\rule{0.16em}{0ex}}^{120}\mathrm{Sn}$ and $\phantom{\rule{0.16em}{0ex}}^{7}\mathrm{Li}+\phantom{\rule{0.16em}{0ex}}^{119}\mathrm{Sn}$, and for a projectile energy range from 17.5 to 28 MeV in the center-of-mass system. A new deconvolution analysis technique is used to link the basic activation data to the actual fusion excitation function. The complete fusion cross sections above the barrier are suppressed by about $70%$ and $85%$ with respect to the universal fusion function, used as a standard reference, in the $\phantom{\rule{0.16em}{0ex}}^{6}\mathrm{Li}$ and $\phantom{\rule{0.16em}{0ex}}^{7}\mathrm{Li}$ induced reactions, respectively. From a comparison of the excitation functions of the two systems at energies below the barrier, no significant differences can be observed, despite the two systems have different $n$-transfer $Q$ values. This observation is supported by the results of coupled reaction channels (CRC) calculations.