Resonant enhancement of dielectronic recombination by a high-frequency microwave field

Dielectronic recombination via the Ba 6p(3/2)nl states from a continuum of finite bandwidth is resonantly enhanced by a 38.8-GHz microwave field at the energies for which the Delta n=1, 2, ..., k transitions of the intermediate 6p(1/2)nl states are resonant with the microwave frequency. The mechanism is resonant Stark mixing of high and low l states by the microwave field. While static field enhancement of dielectronic recombination occurs at fields scaling as n(-5), the field required for enhancement of the Delta n=k, k >= 2 resonances is roughly n independent.