Interplay between quantum shells and orientation in quasi-fission

Abstract

The quasi-fission mechanism hinders fusion in heavy systems through breakup within zeptoseconds into two fragments with partial mass equilibration. Its dependence on the structure of both the collision partners and the final fragments is a key question. Our original approach is to combine an experimental measurement of the fragments' mass-angle correlations in ${}^{40}$Ca${+}^{238}$U with microscopic quantum calculations. We demonstrate an unexpected interplay between the orientation of the prolate deformed ${}^{238}$U with quantum shell effects in the fragments. In particular, calculations show that only collisions with the tip of ${}^{238}$U produce quasi-fission fragments in the magic $Z=82$ region, whilst collisions with the side are the only one which may result in fusion.

5 pages, 4 figures; Accepted for publication in Physical Review Letters

References in corpus (6)

• Particle transfer reactions with the time-dependent Hartree-Fock theory using a particle number projection technique
• Energy dependence of nucleus-nucleus potential close to the Coulomb barrier
• 3-D unrestricted TDHF fusion calculations using the full Skyrme interaction
• Particle number fluctuations and correlations in transfer reactions obtained using the Balian-Vénéroni variational principle
• Collision dynamics of two ${}^{238}$U atomic nuclei
• A new inverse quasifission mechanism to produce neutron-rich transfermium nuclei

Cited by in corpus (17)

• TDHF Theory and Its Extensions for the Multinucleon Transfer Reaction: a Mini Review
• Dissipative dynamics in quasi-fission
• Timescales of quantum equilibration, dissipation and fluctuation in nuclear collisions
• Reduced quasifission competition in fusion reactions forming neutron-rich heavy elements
• Enhanced nucleon transfer in tip collisions of ${}^{238}$U+${}^{124}$Sn
• Time-dependent Hartree-Fock plus Langevin approach for hot fusion reactions to synthesize the $Z=120$ superheavy element
• Exploring Zeptosecond Quantum Equilibration Dynamics: From Deep-Inelastic to Fusion-Fission Outcomes in ${}^{58}$Ni+${}^{60}$Ni Reactions
• Dependence of fusion on isospin dynamics
• Transport properties of isospin asymmetric nuclear matter using TDHF
• Multi-Nucleon Transfer in Central Collisions of ${}^{238}$U + ${}^{238}$U
• Evidence for the role of proton shell closure in quasi-fission reactions from X-ray fluorescence of mass-identified fragments
• Comparison of fission and quasi-fission modes
• Dynamical effects in fusion with exotic nuclei
• Quantal Nucleon Diffusion I: Central Collisions of Symmetric Nuclei
• Simulation of fusion and quasi-fission in nuclear reactions leading to production of superheavy elements using the Constrained Molecular Dynamics model
• Microscopic study of the effect of intrinsic degrees of freedom on fusion
• Time-dependent mean-field investigations of the quasifission process