Statistical model calculations of heavy-ion induced fusion-fission reactions
Statistical model calculations of heavy-ion induced fusion-fission reactions are performed with fission barrier heights, and potential curvatures, at both the equilibrium and saddle points, determined as a function of the total spin, J, the spin about the symmetry axis, K, and the nuclear temperature, T, in a self-consistent manner. The fission saddle points are correctly determined by finding the minimum in the system entropy as a function of deformation along the fission path. It is shown that if the saddle points are incorrectly determined using the turn points in the T=0 potential energy surfaces, that erroneous conclusions can be made regarding the viscosity of nuclear matter. When fission is modeled correctly, vast amounts of heavy-ion induced fission-probability and particle-emission data are consistent with the fission of fully equilibrated systems with the nuclear viscosity determined via the surface plus window dissipation model of Nix and Sierk.