Does break-up affect $^9$Be + $^{209}$Bi fusion at the barrier?

The 9Be +209Bi fusion cross sections were measured in the 36.0 MeV ≤ Elab≤ 50.0 MeV range, down to 0.6 mb, with high accuracy via in-beam detection of the ground state α-decay of the evaporation residues produced. The elastic scattering cross sections around 150° and 135° were also obtained with moderate angular resolution. The cross sections below the barrier are reproduced by coupled channel calculations which include only one break-up channel with a moderate strength and a phenomenological renormalization of the potential depth. These simple calculations overestimate the cross sections above the barrier most likely due to the fact that the 9Be break-up process becomes much stronger. The barrier distributions extracted do not have evident break-up signature since they show one-barrier structure.