Strong Orientation Dependence of Multinucleon Transfer Processes in $^{238}$U+$^{124}$Sn Reaction

TL;DR

This study uses TDHF theory to analyze multinucleon transfer in $^{238}$U+$^{124}$Sn reactions, revealing that transfer depends heavily on the orientation of the deformed uranium nucleus, especially favoring tip collisions due to neck breaking.

Contribution

It demonstrates the strong orientation dependence of multinucleon transfer processes in uranium-tin reactions using a microscopic theoretical approach.

Findings

Transfer amount varies with uranium orientation.

Tip collisions produce more proton transfer due to neck breaking.

Neck formation is suppressed in side collisions.

Abstract

We theoretically investigate multinucleon transfer (MNT) processes in $^{238}$U+$^{124}$Sn reaction at $E_\mathrm{lab}=5.7$ MeV/$A$ using the time-dependent Hartree-Fock (TDHF) theory. For this reaction, measurements of MNT processes have been reported, showing substantial MNT cross sections accompanying more than ten protons. From the calculation, we find that the amount of transferred nucleons depends much on the relative orientation between the deformation axis of $^{238}$U and the relative vector connecting centers of $^{238}$U and $^{124}$Sn nuclei. We find a formation of thick neck when the $^{238}$U collides from its tip with $^{124}$Sn. However, the neck formation is substantially suppressed when $^{238}$U collides from its side. We have found that a large number of protons are transferred in the tip collision. This is caused by the breaking of the neck and subsequent absorption of nucleons in the neck region. We thus conclude that the measured MNT processes involving about ten protons originate from the neck breaking dynamics in the tip collisions of a deformed $^{238}$U nucleus.