Dynamical approach to heavy-ion induced fission using actinide target nuclei at energies around the Coulomb barrier

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, quasi-fission and deep quasi-fission 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 reactions of ${}^{34,36}$S+${}^{238}$U and ${}^{30}$Si+${}^{238}$U at several incident energies around the Coulomb barrier. We find that the time scale in the quasi-fission as well as the deformation of fission fragments at the scission point are different between the ${}^{30}$Si+${}^{238}$U and ${}^{36}$S+${}^{238}$U systems, causing different mass asymmetries of the quasi-fission.

11 figures

References in corpus (2)

• Synthesis of superheavies: State of affairs and outlooks
• Fusion hindrance and roles of shell effects in superheavy mass region

Cited by in corpus (18)

• Interplay between quantum shells and orientation in quasi-fission
• Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in the ${}^{64}$Ni+${}^{238}$U reaction
• Non-Gaussian Fluctuation and Non-Markovian Effect in the Nuclear Fusion Process: Langevin Dynamics Emerging from Quantum Molecular Dynamics Simulations
• Coupled-channels calculations for nuclear reactions: from exotic nuclei to superheavy elements
• Exploring Zeptosecond Quantum Equilibration Dynamics: From Deep-Inelastic to Fusion-Fission Outcomes in ${}^{58}$Ni+${}^{60}$Ni Reactions
• Deformed shell effects in ${}^{48}$Ca+${}^{249}$Bk quasifission fragments
• Hot fusion reactions with deformed nuclei for synthesis of superheavy nuclei: an extension of the fusion-by-diffusion model
• Evidence for the role of proton shell closure in quasi-fission reactions from X-ray fluorescence of mass-identified fragments
• Microscopic analysis of fusion hindrance in heavy systems
• Energy-Dependence of Nucleus-Nucleus Potential and Friction Parameter in Fusion Reactions
• Shell Effects in Quasi-fission in Reactions Forming 226Th Compound Nucleus
• Modes of massive nucleon transfer appearing in quasifission processes for collisions of superheavy nuclei
• Production of super-heavy nuclei in cold fusion reactions
• Constraining the equation of state of nuclear matter from competition of fusion and quasi-fission in the reactions leading to production of the superheavy elements
• Dynamical mechanism of fusion hindrance in heavy ion collisions
• Effects of neck and nuclear orientations on the mass drift in heavy ion collisions
• Nuclear incompressibility and its enduring impact on fusion cross-section
• Isospin effect in peripheral heavy-ion collisions at Fermi energies