Systematic study on fusion evaporation reactions induced by ⁴⁸Ca–⁵⁵Mn projectiles

摘要: A systematic study on fusion evaporation reactions induced by projectiles from ⁴⁸Ca to ⁵⁵Mn for the synthesis of superheavy elements with Z = 112-120 has been performed within the framework of the dinuclear system model. Considering the significant quadrupole deformation of ⁵⁴Cr, the surface diffusion parameter was adjusted to enable a reliable extrapolation of the model to the ⁵⁴Cr-induced reactions. The calculated results show that the evaporation residue cross sections for Z = 112 are consistently larger than those for Z = 113, and beyond this point the cross sections exhibit a bell-shaped trend, rising to Z = 115 (Z = 114 for ⁵⁴Cr-induced reactions) and then decreasing rapidly with increasing atomic number. This behavior is primarily governed by the survival probabilities. The neutron-deficient nature of ⁴⁵Sc, together with its relatively large reaction Q value, causes the corresponding reaction systems to deviate from the overall systematic trend. Predictions for the synthesis of elements Z = 119 and Z = 120 indicate that the reactions ⁴⁵Sc + ²⁴⁹Cf and ⁵⁰Ti + ²⁴⁹Cf are the most promising candidates, with maximum cross sections of 49.22 fb and 6.56 fb, respectively.