Theoretical calculation of the cross sections of dielectronic recombination on He+

The relativistic multichannel theory has been applied to calculations of cross sections of dielectronic recombination on He+. A first-order approximation is adopted for the radiative process. A correction based on isolated resonance approximation is used for the very narrow resonances among the 2lnl′ states to include the radiation width. Twelve partial cross sections are calculated for both the 2lnl′ and 3lnl′ resonance states with n<~5. The convolved cross sections for the n<~3 states are in good agreement with those of the observations. A quantitative discrepancy for the n=4 and n=5 states may be attributed to the l dependence of the field ionization and the radiative decay during the time of flight.