Mixing of fusion-fission and quasifission products inreaction with massive nuclei

It is known the fusion cross section plays crucial role in the choice of the reaction to synthesize new superheavy elements. An estimation of the fusion cross section in the reactions with massive nuclei is difficult task when the mass (charge) and angular distributions of the quasifission and fusion-fission fragments strongly overlap. The measured yields of evaporation residues, fusion-fission and quasifission fragments in the Ca-48+Sm-154 reactions are analyzed in the framework of the method based on the dinuclear system concept and advanced statistical model. The experimental data of the fission fragments are decomposed into contributions coming from fusion-fission, quasifission, and fast fission. Our investigations showed the synthesis of the new element Z=120 (A=302) is more preferable in the Cr-54+(CM)-C-248 reaction in comparison with the Fe-58+Pu-244 and Ni-64+U-238 reactions because the excitation function of the evaporation residues of the former reaction is some orders of magnitude larger than that for the last two reactions.