GLOBAL OPTICAL-MODEL POTENTIALS FOR SYMMETRICAL LITHIUM SYSTEMS - LI-6-6, LI-7+LI-7 AT E(LAB)=5-40 MEV(LI)

Angular distributions of Li-6+Li-6 elastic scattering were measured fo r E(lab) = 5-40 MeV. An optical model analysis of these data together with older data of Li-7+Li-7 elastic scattering taken at E(lab) = 8-17 MeV was performed with the aim to search for a ''global'' OM potentia l which describes elastic scattering in both Li-Li systems in a broad energy range. Both surface and volume absorbing potentials can be foun d which fulfill this requirement if a linear energy dependence is assu med of the depths of the real as well as the imaginary potential. Thes e depths, if fitted to individual angular distributions, are found to vary in a correlated manner with the beam energy. This is taken as ind ication of strong coupling between elastic, inelastic, and reaction ch annels. This is corroborated by the existence of resonances in reactio n channels at these energies where the potential depths are most prono uncedly changing.