Time-dependent Hartree-Fock calculations for multinucleon transfer and quasifission processes in the $^{64}$Ni+$^{238}$U reaction

TL;DR

This study uses three-dimensional time-dependent Hartree-Fock calculations to analyze multinucleon transfer and quasifission in the $^{64}$Ni+$^{238}$U reaction, highlighting the influence of nuclear structure and deformation on reaction dynamics.

Contribution

The paper demonstrates the effectiveness of microscopic TDHF calculations in describing complex nuclear reaction processes involving heavy deformed nuclei.

Findings

Reasonable agreement between TDHF results and experimental data.

Collision dynamics depend on the orientation of deformed $^{238}$U.

Quantum shell effects around $^{208}$Pb significantly influence reaction outcomes.

Abstract

Background: Multinucleon transfer (MNT) and quasifission (QF) processes are dominant processes in low-energy collisions of two heavy nuclei. They are expected to be useful to produce neutron-rich unstable nuclei. Nuclear dynamics leading to these processes depends sensitively on nuclear properties such as deformation and shell structure. Purpose: We elucidate reaction mechanisms of MNT and QF processes involving heavy deformed nuclei, making detailed comparisons between microscopic time-dependent Hartree-Fock (TDHF) calculations and measurements for the $^{64}$Ni+$^{238}$U reaction. Methods: Three-dimensional Skyrme-TDHF calculations are performed. Particle-number projection method is used to evaluate MNT cross sections from the TDHF wave function after collision. Results: Fragment masses, total kinetic energy (TKE), scattering angle, contact time, and MNT cross sections are investigated for the $^{64}$Ni+$^{238}$U reaction. They show reasonable agreements with measurements. At small impact parameters, collision dynamics depends sensitively on the orientation of deformed $^{238}$U. In tip (side) collisions, we find a larger (smaller) TKE and a shorter (longer) contact time. In tip collisions, we find a strong influence of quantum shells around $^{208}$Pb. Conclusions: It is confirmed that the TDHF calculations reasonably describe both MNT and QF processes in the $^{64}$Ni+$^{238}$U reaction. Analyses of this system indicates the significance of the nuclear structure effects such as deformation and quantum shells in nuclear reaction dynamics at low energies.