The potential of the loosely bound 9Be from 209Bi elastic scattering: unusual behaviour at near threshold energy

Precise elastic scattering measurement were done at the Coulomb barrier for the system 9Be+209Bi from 40 to 48 MeV in 2 MeV intervals and 3.5° steps. The deduced Woods–Saxon potential shows a very unusual behaviour that could be connected to the breakup of the weakly bound projectile expected to have a large cross section. The same potential also reproduces the observed inelastic scattering.