Fusion of28Si +28Si: oscillations above the barrier and the behavior down to 1μb

A.M. Stefanini, G. Montagnoli, L. Corradi, S. Courtin, E. Fioretto, J. Grebosz, F. Haas, H.M. Jia, M. Mazzocco, C. Michelagnoli, T. Mijatović, D. Montanari (+16 others)
2014 EPJ Web of Conferences  
Fusion excitation functions of light heavy-ion systems show oscillatory structures above the Coulomb barrier, caused by resonances or due to the penetration of successive centrifugal barriers well separated in energy. In heavier systems, the amplitude of oscillations decreases and the peaks get nearer to each other. This makes the measurements very challenging. We have performed a first experiment for 28 Si + 28 Si, by measuring fusion cross sections (σ) in an energy range of 15 MeV above the
more » ... 15 MeV above the barrier, with a small ∆E lab = 0.5 MeV step. Three regular oscillations are clearly observed, which are best revealed by plotting the energy-weighted derivative of the excitation function. The excitation function has been recently measured down to cross sections ≤1µb with larger energy steps. Coupled-channel (CC) calculations based on a shallow potential in the entrance channel are able to reproduce the oscillations. A further analysis will provide a stringent test for the calculations, in particular for the choice of the ion-ion potential, because the subbarrier excitation function has to be reproduced as well. This is an Open Access article distributed under the terms of Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. the Article available at
doi:10.1051/epjconf/20146603082 fatcat:nezbn4les5hq5gljtf6tux6sma