Results of deep-interactions between complex nuclei - complete and incomplete fusion

Experiments are described in which compound nuclei are formed without any ambiguity. The criteria for determining a true complete fusion by its effects on the observed products, are discussed. The experimental aspects of the limitations on compound nucleus formation, its dependence on the projectile mass, on the kinetic energy and on the orbital angular momentum in the entrance channel, are dealt with. The concept of critical angular momentum for complete fusion, its origins and its theoretical approaches are briefly discussed. The new concept of critical distance is developed. Experimental results of heavy ion reactions are presented which show that some fusion process has occurred, that a large part of the energy has been relaxed, but however, the composite system shortly moves toward a scission of two components. The status of the present knowledge of the influence of nuclear matter viscosity on fusion is considered. (Auth.)