Subbarrier fusion ofLi9withZn70

Abstract

The cross section for the fusion of $^{9}\mathrm{Li}$ with $^{70}\mathrm{Zn}$ was measured for seven projectile energies spanning the subbarrier and near-barrier region (${E}_{\mathrm{c}.\mathrm{m}.}$ ranging from 9.7 to 13.4 MeV) using the ISAC facility at TRIUMF. \ensuremath{\gamma}-ray spectroscopy of the irradiated target foils along with \ensuremath{\beta} counting of the chemically separated Ge and As evaporation residues were used to measure the fusion cross sections. Statistical model calculations were used to correct for the yields of any unobserved nuclei. The observed fusion excitation function shows significant subbarrier fusion enhancement with a large deduced value of the fusion radius, ${R}_{B}=12.1\ifmmode\pm\else\textpm\fi{}1.0$ fm. Coupled-channels calculations do not account for the observed subbarrier enhancement. The implications of this finding for understanding the fusion of $^{11}\mathrm{Li}$ are discussed.