Isotopic dependence of superheavy nuclear production in hot fusion reactions

Abstract

The dependence of the evaporation residue cross section (ERCS)'s ability to produce superheavy nuclei (SHN) on the isospin of colliding nuclei is analyzed within the dinuclear system concept. ERCSs are discussed in detail and compared with existing experimental data. The fusion probabilities and surviving probabilities depend sensitively on the neutron numbers of the target and projectile nuclei. In most cases a neutron excess in the system can increase the producing cross section of a new nuclide of SHN. Some predicted ERCSs for the new isotopes of SHN were found to be as large as about 1--8 pb, which is large enough to be realized experimentally with the current existing technology. Element 120 may be produced by $^{50}\mathrm{Ti}+^{251,252}\mathrm{Cf}$, with the ERCS being about 0.03 pb, and element 119 may be produced by the reaction channel $^{50}\mathrm{Ti}+^{248,249}\mathrm{Bk}$, with the ERCS being about 0.1 pb via $3n$ and $4n$ emission channels, respectively. Radioactive projectiles are not much more favorable in comparison to stable projectiles.