Relativistic Calculation of Dielectronic Recombination on the C⁴⁺ Ground State

The relativistic multichannel theory has been applied and a nonperturbative formula adopted to calculate the dielectronic recombination cross section due to ΔN=1 resonances for the ground state C⁴⁺. The first-order approximation is adopted for the radiative process and a correction based on the isolated resonance approximation is used for the very narrow resonances to include the radiation width. The convoluted cross section is in agreement within 5% with that of observation for resonances with n ≤ 5. For n=6 and 7, the integral cross section is overestimated by a factor of 6 and 4, respectively. According to our calculation, the Rydberg cut-off due to field ionization should be at a principal quantum number higher than that given by Mannervik et al. A Small relativistic effect is noticed at intrashell resonance.