Energy sharing based on microscopic level densities

The transformation of a moderately excited heavy nucleus into two fission fragments is modeled as strongly damped evolution the nuclear shape. resulting Brownian motion in multi-dimensional deformation space guided by shape-dependent level density which has been calculated microscopically for each nearly ten million shapes (given three-quadratic-surfaces parametrization) using previously developed combinatorial method that employs same single-particle levels those used calculation pairing and shell contributions to five-dimensional macroscopic-microscopic potential-energy surface. stochastic shape followed until small critical neck radius reached, at point mass, charge, proto-fragments are extracted. available excitation energy divided statistically on basis microscopic densities associated with distorted fragments. Specific fragment structure features may cause distribution disvision deviate significantly from expectations based Fermi-gas density. After their formation scission, initially being accelerated mutual Coulomb repulsion relax equilibrium forms. distortion converted additional fully These subsequently undergo sequential neutron evaporation again appropriate densities. dependence mean multiplicity well initial fissioning compound nucleus, exhibit similar experimentally observed behavior, suggesting sharing mechanism plays an important role low-energy fission.