Fusion of very heavy nuclei

Abstract

Details of the dynamical nature of the fusion process are beginning to emerge from experiments with heavy targets and projectiles at bombarding energies near and up to twice the barrier energy. Thus, subbarrier fusion is found to be enhanced in a way that cannot be understood as tunneling through a static, one-dimensional, radial potential barrier. Likewise, the extra push concept, which is dynamic in nature, appears more successful in describing fusion excitation functions than for example the critical distance model, which is based on a static, sudden potential in one variable. Finally, the occurrence of the fast fission process seems to be understandable in terms of the cliff hypothesis, which again is dynamic in origin, rather than as a result of energetic instability of the totally fused configuration.