Dielectronic recombination rate coefficient for Cu-like Au⁵⁰ ion

The rate coefficients \alpha^\rm DR of dielectronic recombination (DR) for Cu-like Au^50+ ion collided with the incident free electron are calculated based on the quasi-relativistic multi-configuration Hartree－Fock theory. The results clearly show that the \alpha^\rm DR of all recombination channels exhibits resonance characters with electron temperature. At lower temperatures, the recombination for electrons caused by 4s excitation is dominant through outer electron radiative transitions among the intermediate doubly excited autoionizing levels, in which the most components come from 3d^105pns states, whereas with increasing electron temperature, DR caused by 3d excitation turns out to be dominant, and the contribution from the 3d^94s4fnf state to the total rate coefficient of electron 3d is the largest with \alpha^\rm DR=1.15\times10^- 11 cm^3\cdots^-1 at an electron temperature of T_\rm e=0.35 keV. Under this condition, there exists a strong competition between the two types of recombination channels.