Elastic scattering for the system ¹¹Be + ²⁰⁹Bi at Coulomb barrier energies

The elastic scattering process for Be-11 ions impinging on a Bi-209 target was studied in the energy range around the Coulomb barrier. The angular distributions of the Be-11 scattered particles were analyzed within the optical model framework in order to evaluate the reaction cross section, which turned out to be much larger than the fusion one, especially in the sub-barrier region. The comparison with the system Be-9 + Bi-209 showed that the reaction cross section is larger for the reaction Be-11 + Bi-209 in the energy range around the Coulomb barrier, while they are rather similar at higher bombarding energies. This result suggests that direct processes related to the Be-11 halo structure and lower binding energy are more relevant at near-barrier energies.