(1990 - 1991) DOCTORATE DEGREE

The topics discussed in the Doctorate degree (Laurea) thesis, entitled “Nucleus-nucleus optical potential microscopic calculations”, deal with the microscopic description of the potential which is responsible for the elastic scattering between two heavy ions.
Within this framework, the dynamical polarization potential arising from the coupling of the elastic channel to the collective vibrational states of the nucleus has been calculated, evaluating also the contribution of the single-nucleon exchange corrections to the folding potential due to the exact symmetry of the wave function used to describe the nuclear system.
Particular attention has been done in the calculation of the contributions of the low lying and high lying nuclear states to the real and imaginary parts of the polarization potential, showing the importance of the high lying states and their contribution to the real part at every incident energy, whereas they dominate the imaginary part only at very high energy.
In order to check the range of validity of the previous results, calculations have been performed for the systems ¹⁶O+⁴⁰Ca (at beam energy of 104 MeV) and ⁴⁰Ca+⁴⁰Ca (at beam energy of 143 MeV).
The agreement of the experimental elastic cross sections data with the calculations is very good, considering also that calulcations have been done with no adjustable parameters.