Collisional-Radiative Recombination of He2+ into Dissociative States

Spectroscopic investigation of a flowing helium afterglow revealed the presence of strong 10 830-Å atomic helium emission corresponding to the 23P→23S transition, which could be quenched by the application of a weak microwave field to the afterglow. An examination of the axial variation and pressure dependence of the concentration of 23P atoms established that it resulted primarily from the ion—electron recombination of He2+, rather than He+, at the higher pressures examined. An extension of the theory of collisional-radiative recombination of molecular ions to include dissociating states is postulated to explain these observations.