IOPscience - Scattering of 6He at energies around the Coulomb barrier

We have measured elastic cross sections of the scattering of 6He at ELab = 14, 16, 17, 18 and 22 MeV on 208Pb in the angular ranges of 20°–64° and 135°–170°. A significant amount of 4He events is found at energies well below the Coulomb barrier, that becomes dominant above it. Optical model calculations have been performed including a dynamic polarization potential. Very large imaginary diffuseness parameter is needed in order to describe the experimental distributions.