Excited species in H2, N2, O2 microwave flowing discharges and post-discharges

The density of O and H atoms have been measured by emission spectroscopy and by catalytic probes in a flowing post-discharge reactor. In the post-discharge reactor at 1 torr and a time of 2–3×10−2 s after a 2.45-GHz Ar10%O2 discharge (quartz tube of diameter 6 mm) at 60 W, approximately the same values of 1(±0.3)×1015 cm−3 oxygen atom densities were obtained by NO titration and by a Ni catalytic probe. In ArH2 post-discharge, the Ni catalytic probe gave a H-atom density of (1–1.2)×1015 cm−3 for an Ar4%H2 gas mixture at 3 torr and a time less than 10−3 s after a microwave discharge of 50 W.