Refractive effects and nuclear molecules in light heavy ions collisions

Collisions between heavy ions are generally commanded by the strong absorption and the fusion mechanism, with a formation of composed nucleus. Meanwhile for some collisions between light heavy ions, the nucleus can't absorb the most important angular momentum introduced in the system. This leads to the interaction transparency for the more peripheral collisions. This transparency may give resonant effects with formation of nuclear molecules and/or for shorter interaction times retracting effects leading to interference phenomena (Airy structure, nuclear rainbow). Resonant phenomena have been studied for the system 18O + 12C and retracting effects for the systems 16O + 16O and 16O + 12C. These experiments have been realized at the Vivitron, the electrostatic accelerator of Strasbourg (France). (A.L.B.)