The origin of the oscillations in the fusion excitation function for the ${}_{}{}^{12}{}_{}{}^{}$C${+\mathrm{}}^{12}$C system is investigated in the framework of the optical model using the concept of internal and barrier waves. It is found that the oscillations are caused by the interference of internal and barrier waves, which satisfy a destructive interference condition. The internal wave also plays an important role in reproducing the correct magnitude of the fusion cross section.

• Received 11 December 1986

DOI:https://doi.org/10.1103/PhysRevC.36.1375