C.J. Lin

Influence of entrance-channel magicity and isospin on quasi-fission

The role of spherical quantum shells in the competition between fusion and quasi-fission is studied for reactions forming heavy elements. Measurements of fission fragment mass distributions for different reactions leading to similar compound nuclei have been made near the fusion barrier. In general, more quasi-fission is observed for reactions with non-magic nuclei. However, the

Effects of Nuclear Structure on Quasi-fission

^{40}

Dynamics and Time-scales in Breakup and Fusion

Ca+

Investigating quasi-fission dynamics through mass-angle distributions

^{208}

Insights into the mechanisms and time-scales of breakup of 6,7 Li

Pb reaction is an exception, showing strong evidence for quasi-fission, though both nuclei are doubly magic. Time-dependent Hartree-Fock calculations predict fast equilibration of

Mapping quasifission characteristics and timescales in heavy element formation reactions

N/Z

Predominance of transfer in triggering breakup in sub-barrier reactions of 6,7Li with 144Sm, 207,208Pb, and 209Bi

in the two fragments early in the collision. This transfer of nucleons breaks the shell effect, causing this reaction to behave more like a non-magic one in the competition between fusion and quasi-fission. Future measurements of fission in reactions with exotic beams should be able to test this idea with larger

Systematic behavior of mass distributions in 48 Ti-induced fission at near-barrier energies

N/Z

SOLEROO: A solenoidal exotic rare isotope separator at the Australian National University

asymmetries.

Reaction dynamics of weakly bound nuclei at near-barrier energies

The quasi-fission mechanism hinders fusion of heavy systems because of a mass flow between the reactants, leading to a re-separation of more symmetric fragments in the exit channel. A good understanding of the competition between fusion and quasi-fission mechanisms is expected to be of great help to optimize the formation and study of heavy and superheavy nuclei. Quantum microscopic models, such as the time-dependent Hartree-Fock approach, allow for a treatment of all degrees of freedom associated to the dynamics of each nucleon. This provides a description of the complex reaction mechanisms, such as quasi-fission, with no parameter adjusted on reaction mechanisms. In particular, the role of the deformation and orientation of a heavy target, as well as the entrance channel magicity and isospin are investigated with theoretical and experimental approaches.