Effect of entrance channel on dynamics of heavy ions collision.

A combined dynamical model using concept of dinuclear systems (DNS) and one-dimensional (1D) Langevin equations was applied to investigate the effect of entrance channel on dynamics of heavy ions collision. The Si+Er, O+W and F+Ta reactions which formed the compound nucleus Pb have been considered to study this effect. We studied these reactions dynamically and calculated the ratio of evaporation residue cross-section to fusion cross-section as a tool for investigation of entrance channel effect. Results of combined model are compared with available experimental data and results of 1D Langevin equations. Obtained results based on combined model are in better agreement with experimental data in comparison with results of Langevin equations. We concluded for Si+Er and F+Ta reactions the results of combined model that support the quasi-fission process are different relative to Langevin dynamical approach, whereas for O+W system the two models give similar results. [ABSTRACT FROM AUTHOR]