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The fusion probability for heavy symmetric systems is known to show certain very specific features. Apart from the large variance of the fusion barrier distribution, it is found that the energy at which the s‐wave transmission is 0.5 is shifted to an energy significantly higher than the nominal (e.g. Bass) Coulomb barrier. This last feature is referred to in the literature as the ‘extra push’ effect. Many models have been devised to explain the origin of these findings. It is worth noting, however, that despite the extra push, the capture cross section is still greatly enhanced at the very lowest energies. This fact cannot be explained within the framework of macroscopic theories involving conditional saddle points or frictional forces. We have performed full coupled‐channel calculations for heavy, symmetric systems treating correctly the long‐range Coulomb excitations of the collective quadrupole‐ and octupole‐phonon states in the target and projectile. The results obtained show that the extra push and t...

Results of the experiments aimed at the study of fission and quasi‐fission processes in the reactions 12C+204Pb, 48Ca+144,154Sm, 168Er, 208Pb, 238U, 244Pu, 248Cm; 58Fe+208Pb, 244Pu, 248Cm, and 64Ni+186W, 242Pu are presented. The choice of the above‐mentioned reactions was inspired by the experiments on the production of the isotopes 283112, 289114 and 283116 at Dubna using the same reactions. The 58Fe and 64Ni projectiles were chosen since the corresponding projectile‐target combinations lead to the synthesis of even heavier elements. The experiments were carried out at the U‐400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Russia), the XTU Tandem accelerator of the National Laboratory of Legnaro (LNL, Italy) and the Accelerator of the Laboratory of University of Jyvaskyla (JYFL, Finland) using the time‐of‐flight spectrometer of fission fragments CORSET and the neutron multi‐detector DEMON. The role of shell effects and the influence of the entrance channel asymmetry and the deformatio...