PRODUCTION OF N, H, AND NH ACTIVE SPECIES IN N-2-H(2) DC FLOWING DISCHARGES

Densities of N, H, and NH active species have been detected by laser-induced fluorescence (LIF) in N-2-xH(2) dc flowing discharges. A peak value of N atom densities for x=0.2-0.5% and a plateau value of H atom densities between x = 1% and 90% in post-discharge conditions (Delta t similar to 0.05 sec, p = 2 torr) has been found. Comparison between LIF measurements of N atoms and the trend of the N-2(B, upsilon = 11) population shows that the emission from this state can be used for monitoring N atoms. The NH radical has only been detected inside the discharge region.