Study of the quadrupole deformation parameter in heavy and superheavy nuclei

In this paper, the potential energy surfaces of nuclei with atomic numbers Z=90-100 within the microscopic-macroscopic Cranked Nilsson-Strutinsky (CNS) formalism are studied, and the axial quadrupole deformation parameter for these isotopes has been calculated. Our calculations showed that the nuclei in this mass region have an average deformation about ε2=0.2 in the ground state and an average deformation about ε2=0.6 in the isomeric state. With increasing the neutron number or proton number, the axial quadrupole deformation increases slightly, and the potential minima appear at a relatively larger deformation. Therefore, in the studied mass region, the nucleus will be more elongated with increasing the mass number. Also the effect of change of spin on the fission barrier height is studied. The results obtained from the CNS model was compared with the experimental results and also the results of other theoretical models. This comparison showed that the CNS models, as well as the HFBCS model have the better accuracy in comparison with the other models, and so these are the proper models to produce the quadrupole deformation parameters of heavy and superheavy nuclei.