SHELL CORRECTION ENERGY AND THE ENTRANCE CHANNEL EFFECT ON THE FORMATION OF SUPERHEAVY NUCLEI

Abstract

Based on the improved isospin dependent molecular dynamics model in which the shell correction energy of the system is calculated by using deformed two-center shell model and the surface energy of the system is improved by introducing a switch function that combines the surface energies of projectile and target with the one of the compound nucleus. The effects of the shell correction energy on synthesis of superheavy nuclei and the fusion cross sections in asymmetric and nearly symmetric reaction systems leading to the same compound nuclei 62 Zn , 76 Kr , and 202 Pb are studied. The entrance channel mass asymmetry dependence of compound nucleus formation is found by analyzing the shell correction energies, Coulomb barriers and fusion cross sections. The experimental data are described quantitatively by the present model. It is found that the compound nucleus formation is favorable for the systems with larger mass asymmetry.