Dynamical approach to fusion-fission process in superheavy mass region

¹ Flerov Laboratory of Nuclear Reactions, JINR, Dubna, 141980, Russia
² Japan Atomic Energy Agency, Tokai, Ibaraki, 319-1195, Japan
³ Department of Nuclear Physics, Research School of Physics and Engineering, The Australian National University, ACT 0200, Australia
⁴ Department of Physics, Tohoku University, Sendai 980-8578, Japan
⁵ Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550, Japan

^a e-mail: aritomo24@muj.biglobe.ne.jp

Abstract

In order to describe heavy-ion fusion reactions around the Coulomb barrier with an actinide target nucleus, we propose a model which combines the coupled-channels approach and a fluctuation-dissipation model for dynamical calculations. This model takes into account couplings to the collective states of the interacting nuclei in the penetration of the Coulomb barrier and the subsequent dynamical evolution of a nuclear shape from the contact configuration. In the fluctuation-dissipation model with a Langevin equation, the effect of nuclear orientation at the initial impact on the prolately deformed target nucleus is considered. Fusion-fission, quasifission and deep quasifission are separated as different Langevin trajectories on the potential energy surface. Using this model, we analyze the experimental data for the mass distribution of fission fragments (MDFF) in the reaction of ³⁶S+²³⁸U at several incident energies around the Coulomb barrier.