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 thr ee independent shape coordinates: separation distance between the frag ment centres; mass asymmetry, and neck radius. The Yukawa-plus-exponen tial model gives the macroscopic energy. Shell and pairing (microscopi c) corrections are calculated on the basis of a superasymmetric two-ce ntre shell model. Various spherical magic numbers in the region of sup erheavy nuclei are obtained by changing the strength of the spin-orbit coupling in the two-centre shell model. A complete set of kappa and m u values have been obtained leading to magic numbers up to 126 for pro tons and 184 for neutrons (including Z = 114, 120 and N = 172). Potent ial energy surfaces for nuclei (280)108, (298)114, and (304)120, plott ed versus the separation distance and mass asymmetry. Compact shapes, typical for synthesis by fusion reactions or cold fission, are assumed .