PRODUCTION OF N-2(A3SIGMA-U+) IN THE LOW-PRESSURE DIELECTRIC-BARRIER (OZONIZER) DISCHARGE

The authors constructed a dielectric-barrier discharge which operates at 1 to 10 kV in flowing nitrogen or nitrogen mixtures with either argon or helium at total pressure between 0.3 and 6 Torr. Spectroscopic observations in the afterglow of this discharge indicate that virtually all observed excitation between 200 and 850 nm results from discharge streamers. All emissions are quenched upon adding a grounded loop downstream from the discharge. The absence of NO gamma-band emission when NO is added downstream from the grounded loop indicates that N2(A) number densities in the afterglow are below 105 molecules cm-3, some ten orders of magnitude below previous estimates.