Complete fusion of nuclei within the framework of the Dinuclear System Concept

A non-traditional approach to the description of the process of complete fusion of nuclei - 'The Dinuclear System Concept (DNSC)' is discussed. The DNSC is based on the idea of similarity of complete fusion and deep inelastic transfer reactions, which provides us with the unique information on the interaction of two nuclei after the full dissipation of collision kinetic energy. The DNSC reveals two important peculiarities of complete fusion of massive nuclei: the existence of a specific inner fusion barrier Bfus* and the competition between the complete fusion and quasi-fission channels in the dinuclear system, which is formed in the capture stage. The DNSC was applied to the analysis of reactions used for the synthesis of trans-fermium (TFE) and superheavy elements (SHE). The minimum excitation energy of compound nuclei produced in the cold fusion reactions was calculated. A decisive role of quasi-fission in decreasing the production cross section with increasing the atomic number of an element was revealed. The cross sections of TFE and SHE synthesized in cold and warm fusion reactions were calculated, including the synthesis of element 118 in the reaction 208 Pb + 86 Kr(-1n). The obtained results indicate that today it is the DNS concept that provides the most realistic description of the complete fusion process in reactions between two nuclei. (author)