Dielectronic Recombinat ion on He⁺ with Non-isolated Resonance Approach

Based on the relativistic multichannel theory, a non-isolated resonance approach has been developed to calculate the cross sections of dielectronic recombination on He⁺ for Δn = 1 and 2 transitions. A first order approximation is adopted for the radiative process. The convolved cross sections for the n≤ 3 states in both transitions are in good agreement with those of the observations. It is shown that the l-dependence of the field ionization and the radiative decay during the time-of-flight affect significantly the measurement of the cross sections near the initial state of the field ionization.