Atmospheric pressure, radio frequency, parallel plate capacitively coupled plasma - excitation temperatures and analytical figures of merit

Electronic excitation (T-exc) and rotational (T-rot) temperatures were determined for a parallel plate capacitively coupled rf plasma operating at atmospheric pressure. T-exc was calculated from the slope of the Boltzmann plot using Fe and He as the thermometric species and Ph excitation temperature was calculated using the two line method. Over a power range from 100 W to 250 W, excitation temperatures are 3255-3900 K for He, 3540-4500 K for Pb, and 4300-4890 K for Fe. The rotational temperature was measured using both OK and N-2(+) molecular spectra and the values are in the range of 828-911 K and 845-956 K respectively over a power range of 75-275 W. Signal-to-noise ratios, signal-to-background ratios, and absolute detection limit for lead (0.33 ng) and silver (24 pg) are also reported. (C) 1997 Elsevier Science B.V.