Speaker
Description
One of the most interesting problems in heavy-ion physics is an identification of the reactions which are called deep-inelastic collisions, quasifission and fusion-fission. These reactions are called binary reactions and their mechanisms are in competition to synthesis of superheavy elements in the different stages of formation of evaporation residue which is considered as a superheavy element. The products of the binary reactions are characterized by the angular, mass (charge) and energy distributions. The mass distribution of quasifission products can overlap with the products of deep-inelastic collisions but the difference between their angular and energy distributions allow us to separate them at analysis of the experimental data.
By using dinuclear system (DNS) model the capture and fusion cross sections are calculated for the reactions $^{34}$S+$^{208}$Pb and $^{36}$S+$^{206}$Pb which are leading same compound nucleus (CN) $^{242}$Cf. The characteristics of the reaction products and cross sections are determined by the properties of the intermediate DNS formed at the capture stage of the projectile nucleus by the target nucleus. The behavior of the DNS depends on the initial beam energy, angular momentum and properties of the interacting nuclei such as shape and shell effects.
The difference between fusion cross sections at the energy near to Coulomb barrier is studied to explain the phenomenon observed in the JAEA [1]. The results show that at the energy near to Coulomb barrier the capture occurs for the wide range of angular momentum in the reaction $^{36}$S+$^{206}$Pb comparing to the $^{34}$S+$^{208}$Pb. However, the difference between observed cross sections of the evaporation residues of the $^{34}$S+$^{208}$Pb and $^{36}$S+$^{206}$Pb reactions formed in the 2n and 3n channels has been explained by the effect of the $N/Z$-ratio in colliding nuclei at formation of the DNS during the capture and its transformation into a compound nucleus.
- J. Khuyagbaatar, et al., Phys.Rev. C 86, 064602 (2012)
