Synthesis of superheavy element 120 via ⁵⁰Ti+^ACf hot fusion reactions

Synthesis of superheavy element 120 in terms of the ⁵⁰Ti+^249-252Cf fusion-evaporation reactions is evaluated and discussed. It is found that the reactions of ^250,251Cf(⁵⁰Ti,3n)^297,298120 and ^251,252Cf(⁵⁰Ti,4n)^297,298120 are relatively favorable with the maximum evaporation-residue cross sections of 0.12, 0.09, 0.11, and 0.25 pb, respectively. However, ²⁵²Cf may be difficult to be target because its spontaneous fission will bring about serious background in the experiment. Fusion probabilities for different target-projectile combinations leading to the formation of surperheavy nucleus ³⁰²120 are estimated with the “fusion-by-diffusion” model and presented as a function of the Coulomb parameter Z₁Z₂/(A₁^1/3+A₂^1/3). Among the reactions ⁵⁰Ti+²⁵²Cf, ⁵⁴Cr+²⁴⁸Cm, ⁵⁸Fe+²⁴⁴Pu, and ⁶⁴Ni+²³⁸U, the reaction ⁵⁰Ti+²⁵²Cf has the largest fusion probability. Synthesis of superheavy element 120 is of essential importance for determining whether the magic proton shell should be at Z=114 or at higher proton numbers Z=120–126. Therefore, the experiment to produce isotopes with Z=120 in the fusion reactions ⁵⁰Ti+^250,251Cf is of great interest.