Isotopic Dependence of Production Cross Sections of Superheavy Nuclei in Hot Fusion Reactions
- Received Date: 2006-08-01
- Accepted Date: 2006-09-06
- Available Online: 2007-04-05
Abstract: The dinuclear system model has been further developed by introducing the barrier distribution function method in the process of heavy-ion capture and fusion to synthesize superheavy nuclei. The capture of two colliding nuclei, formation and de-excitation process of compound nucleus are decribed by using empirical coupled channel model, solving master equation numerically and statistical evaporation model, respectively. Within the framework of the di-nuclear system model, the fusion-evaporation excitation functions of the systems 48Ca(243Am, 3n—5n)288—286115 and 48Ca(248Cm, 3n—5n)293—291116 are calculated, which are used for synthesizing new superheavy nuclei at Dubna in recent years. Isotopic dependence of production cross sections with double magic nucleus 48Ca bombarding actinide targets U,Np,Pu,Am,Cm to synthesize superheavy nuclei with charged numbers Z=112—116 is analyzed systematically. Based on these analysis, the optimal projectile-target combination and the optimal excitation energy are proposed. It is shown that shell correction energy and neutron separation energy will play an important role on the isotopic dependence of production cross sections of superheavy nuclei.