Deformation energy of superheavy nuclei

We study the nuclear deformation energy of superheavy nuclei by using the macroscopic-microscopic method. Nuclear shape is determined by three independent shape coordinates: separation distance between the fragment centres; mass asymmetry, and neck radius. The Yukawa-plus-exponential model gives the macroscopic energy. Shell and pairing (microscopic) corrections are calculated on the basis of a superasymmetric two-centre shell model. Various spherical magic numbers in the region of superheavy nuclei are obtained by changing the strength of the spin-orbit coupling in the two-centre shell model. A complete set of kappa and mu values have been obtained leading to magic numbers up to 126 for protons and 184 for neutrons (including Z = 114, 120 and N = 172). Potential energy surfaces for nuclei (280)108, (298)114, and (304)120, plotted versus the separation distance and mass asymmetry. Compact shapes, typical for synthesis by fusion reactions or cold fission, are assumed.