COMPETITION BETWEEN COMPLETE FUSION AND QUASI-FISSION IN DINUCLEAR SYSTEM

A model based on the dinuclear system concept is suggested for the cal culation of the competition between complete fusion and quasi-fission in reactions with heavy nuclei. The fusion rate through the inner fusi on barrier in mass asymmetry is found by using the Kramers-type expres sion. The calculated cross-sections for the heaviest nuclei are in a g ood agreement with the experimental data. The experimentally observed rapid fall-off of the cross-sections of the cold fusion with increasin g charge number Z of the compound nucleus is explained.