Shell effects in fission, quasifission and multinucleon transfer reaction

International Symposium on Entrance Channel Effect on the Reaction Mechanism in Heavy Ion Collisions

Kozulin, E.M.^1 ; Knyazheva, G.N.^1 ; Itkis, I.M.^1 ; Kozulina, N.I.^1 ; Loktev, T.A.^1 ; Novikov, K.V.^1 ; Harca, I.^1

FLNR, Joint Institute for Nuclear Research, 141980 Dubna, Russia^1

关键词: Basic characteristics;    Channel asymmetry;    Coulomb barrier;    Energy distributions;    Fragment mass distribution;    Fusion-Fission;    Multinucleon transfer reactions;    Shell structure;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/515/1/012010/pdf
DOI  :  10.1088/1742-6596/515/1/012010

来源: IOP

【 摘 要 】

Results of the study of mass-energy distributions of binary fragments for a wide range of nuclei with Z= 82-122 produced in reactions of ions located between22Ne and136Xe at energies close and below the Coulomb barrier are reported. The role of the shell effects, the influence of the entrance channel asymmetry and the deformations of colliding nuclei on the mechanism of the fusion-fission, quasifission and multinucleon transfer reactions are discussed. The observed peculiarities of the mass and energy distributions of reaction fragments are determined by the shell structure of the formed fragments. Special attention is paid on the symmetric fragment features in order to clarify the origin of these fragments (fission or quasifission). The influence of shell effects on the fragment yield in quasifission and multinucleon transfer reactions is considered. It is noted that the major part of the asymmetric quasifission fragments peaks around the region of the Z=82 and N=126 (double magic lead) and Z=28 and N=50 shells; moreover the maximum of the yield of the quasifission component is a mixing between all these shells. Hence, shell effects are everywhere present and determine the basic characteristics of fragment mass distributions.