Refractive effects in the elastic scattering of light heavy ions between 5 and 10 MeV/n: the 16O + 16O reaction

Complete angular distributions of the 16 O + 16 O elastic channel have been measured at the 9 following bombarding energies: E lab = 75.0, 80.6, 87.2, 92.4, 94.8, 98.6, 103.1, 115.9 and 124 MeV using at forward angles ( θ lab = 5° to 20°) the Q3D spectrometer and at backward angles ( θ lab = 20° to 50°) two Position Sensitive Silicon detectors in kinematical coincidence. Refractive effects giving rise to nuclear rainbows and the associated Airy structures have been observed for this system. An optical model analysis has been done where the real part of the potential has been determined with no ambiguity over the whole energy range whereas the absorption (imaginary part) changed drastically around E lab = 90 MeV.