Calculation of fission barriers with the droplet model and folded Yukawa single-particle potential

Abstract

Abstract Single-particle levels in a folded Yukawa potential are studied as functions of various types of distortions. Some level diagrams are plotted versus an elongation coordinate in the fission direction. The levels are also plotted as functions of the asymmetric coordinate ϵ 35 . The levels are labeled by their asymptotic quantum numbers.These diagrams thus show the calculated single-particle level structure at the second minimum and second peak in the fission barrier for nuclei in the actinide region. Fission barriers are calculated by the use of the macroscopic-microscopic method; the macroscopic part of the energy is obtained from the droplet model of Myers and Swiatecki. The relevant equilibrium points in the fission barrier are tabulated for the actinide elements and also for some lighter elements in the region 76 ≦ Z ≦ 84. The calculated energies of the equilibrium points reproduce experimental values to within an accuracy of 1 or 2 MeV. A detailed comparison is made between the three-quadratic-surface parametrization and the ϵ-coordinates in Nilsson's perturbed-spheroid parametrization.