PRODUCTION OF ACTIVE SPECIES IN A COMMON FLOWING POSTDISCHARGE OF AN AR-N2 PLASMA AND AN AR-H2-CH4 PLASMA

A common flowing post-discharge of an Ar-N2 plasma and an Ar-H-2-CH4 p lasma has been used to produce nitrogen and carbon atoms. The concentr ations of the nitrogen and carbon atoms have been determined by NO tit ration and from measurement of the vibrational band intensities of the spectra emitted by the N + N and C + N chemiluminescent reactions. Fo r plasmas created with microwave powers of 40-100 W and for total gas densities of 5 x 10(17) cm-3, typical values for the atom densities of 10(15) cm-3 for nitrogen and 10(11)-10(13) cm-3 for carbon are obtain ed after a residence time of 25 ms in the post-discharge.