Work

Shell effects in quasi-fission for calcium induced reactions forming thorium isotopes

Year: 2025

Type: article

Abstract: Quantum shell effects induce an asymmetric fission mode in actinides, which disappears in neutron deficient isotopes. Quasi-fission, characterized by a significant mass transfer in heavy ion collisions at low-energies, is expected to be affected by similar shell effects. This is studied in 40 − 56 Ca + 176 Yb reactions with the time-dependent Hartree-Fock approach. All reactions exhibit a mass equilibration process that stops when a heavy fragment with Z ≃ 54 protons is formed. Unlike the fission of thorium compound nuclei, quasi-fission does not exhibit a transition to symmetric modes in neutron deficient systems. This observation is interpreted in terms of potential energy surfaces that show a persistence of an asymmetric valley with an increasing barrier preventing its population in fission of the most neutron deficient thorium isotopes.

Source: Physics Letters B

DOI: 10.1016/j.physletb.2025.139955

Authors: C. Simenel, A.S. Umar, K. Godbey, P. McGlynn

Institutions: Australian National University, Vanderbilt University, Facility for Rare Isotope Beams, Michigan State University

Language: English

Topic: Nuclear physics research studies

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond