The fusion of $^{9,11}$Li with $^{70}$Zn*

The fusion of $^{9,11}$Li with $^{70}$Zn was studied at the ISAC1 facility at TRIUMF. Beams of $^{9}$Li (11-14.5 MeV) struck $\approx$ 1 mg/cm$^{2}$ $^{70}$Zn targets in an evacuated scattering chamber. Beam intensities were monitored by measuring elastic scattering and by the use of a Faraday cup for $^{9}$Li while the $^{11}$Li beam was counted in a semiconductor detector placed behind the target. Typical $^{9}$Li beam intensities were 5 x 10$^{6}$ particle/s while the $^{11}$Li intensities were 800 particles/s. As and Ge evaporation residues were assayed using gamma and beta spectroscopy following post-irradiation chemical separation from the irradiated targets. A seven point excitation function for the $^{9}$Li + $^{70}$Zn reaction was measured and compared to coupled channels calculations. Due to the low $^{11}$Li beam intensity, only upper limits for fusion of $\approx$ 2b could be established for $^{11}$Li.