Electric-field-induced mixing of high Rydberg-state levels in dielectronic recombination: Mg/sup 1 +/ and Ca/sup 1 +/ target ions

The effect on the dielectronic recombination cross section of electric-field-induced mixing of high Rydberg-state (HRS) levels is determined, for both Mg/sup +/ and Ca/sup +/ target ions. After diagonalizing the energy matrix, sigma/sub n//sup DR/ is calculated in the isolated resonance approximation as a function of n, the principal quantum number of the HRS electron. From this result, both the total cross section, sigma/sup DR/equivalentsummation sigma/sub n//sup DR/, and the total cross section integrated over energy, ..cap omega../sup DR/equivalent..integral.. de/sub c/ sigma/sup DR/, are obtained. The agreement between theory and experiment for ..cap omega../sup DR/ is very good in the case of Mg/sup +/, while roughly a factor of 2 discrepancy still exists for Ca/sup +/.