TEMPERATURES OF TESLA DISCHARGES FROM OH A-]X INTENSITY MEASUREMENTS

The OH A2Σ+ → X2Π system is used as a diagnostic tool for temperature measurements of Tesla discharges in Ar and He seeded with 0.5 torr H2O. From relative intensities of low-N′ lines in the 0-0 band we obtain temperatures which are independent of pressure for the range 100-650 torr and which are only a few degrees higher than the estimated wall temperatures. A check on the theoretical line strengths for OH A → X shows 1% agreement for main-branch transitions but only 5% agreement for satellite lines. Self-absorption problems are encountered and corrected for in the He discharge work; from the ≈10% magnitude of the correction, there are significant amounts (8 mtorr) of ground-state OH produced in the He Tesla discharge. © 1979.