Estimating fission-barrier height by the spherical-basis method

Abstract

A novel method of estimating fission-barrier heights is presented in this paper, in which potential energy surfaces are calculated by using the spherical-basis method. This method is based on the idea of configuration mixing of various spherical states for deformed nuclei, which gave the ground-state nuclear-mass calculation presented by our group [H. Koura, T. Tachibana, M. Uno, and M. Yamada, Prog. Theor. Phys., 113, 305 (2005)]. Under the restriction of symmetric fission, a systematical fission-barrier calculation is performed in the heavy and superheavy nuclear-mass region, and some higher (neighboring 252Fm, known) and lower (neighboring 278Ds, unknown) fission-barrier regions are found in the nuclear-mass chart; the origin of these appearances is discussed in the framework of the spherical-basis method. The calculated nuclei are also located in the unknown neutron-deficient superheavy nuclear-mass region, where nuclear fission determines a limit on the existence of nuclei. Three regions that have relatively high fission barriers are predicted in neutron-deficient regions having neutron numbers of around 126, 184, and 228.