Abstract
The decay of the nucleus, formed in entrance channel reactions and at different incident energies, is studied by using the dynamical cluster-decay model (DCM) extended to include the deformations and orientations of nuclei. The main decay mode here is fission. The other (weaker) decay channels are the light particles evaporation () and intermediate mass fragments (). All decay products are calculated as emissions of preformed clusters through the interaction barriers. The calculated fission cross sections , taken as a sum of the energetically favored symmetric and near symmetric fragments ( and plus complementary fragments) show an excellent agreement with experimental data at all experimental incident c.m. energies for both reactions, except for the top three energies in the case of the reaction. The disagreement between the DCM calculations and data at higher incident c.m. energies for the entrance channel is associated with the presence of additional effects of noncompound, quasifission (qf) components, in contradiction with the measured anisotropy effects which indicate the other entrance channel to contain the noncompound nucleus contribution. The prediction of two fission windows, the symmetric fission (SF) and near symmetric or heavy mass fragments (HMFs), suggests the presence of a fine structure of fission fragments, which also need an experimental verification. The only parameter of the model is the neck length parameter whose value is shown to depend strongly on limiting angular momentum, which in turn depends on the use of sticking or nonsticking moment of inertia for angular momentum effects.
2 More- Received 24 March 2008
DOI:https://doi.org/10.1103/PhysRevC.77.054613
©2008 American Physical Society