Effect of Coster-Kronig transition on dielectronic recombination of the He-like ions

Abstract

Dielectronic recombination rate coefficients have been calculated for He-like ions with atomic numbers Z=5, 6, 7, 8, and 9. The calculations include the influence of the Coster-Kronig channels to the excited states of the recombining ion on the rate coefficients. The detailed Auger and radiative rates were calculated using the multiconfiguration Dirac-Fock model in intermediate coupling with configuration interaction. The total dielectronic recombination coefficients for ${\mathrm{B}}^{3+}$, ${\mathrm{N}}^{5+}$, and ${\mathrm{F}}^{7+}$ ions have been found to reduce by 60%, 13%, and 4%, respectively, due to the inclusion of Coster-Kronig channels. For the ${\mathrm{B}}^{3+}$ ion, the dielectronic recombination coefficient from the present work is smaller than the value derived from the Burgess-Merts formula by a factor of 3 at electronic temperature T=100 eV.