EXCHANGE PART OF THE REAL HEAVY-ION OPTICAL-POTENTIAL WITHIN THE DOUBLE-FOLDING MODEL AND THE NUCLEAR-MATTER APPROACH

The exchange part of the real heavy-ion optical potential is calculated within a generalised version of the double-folding model. The intrinsic energy dependence of the optical potential originated from the knock-on exchange effects is studied in detail. A comparison with the potentials calculated within the nuclear matter approach is made to show the role of the Pauli principle in the energy dependence of the potential. The optical model analyses of the elastic 16O and 12C scattering data at intermediate energies show that the correct treatment of the exchange potential leads to a more realistic shape of the real optical potential.