発光強度による励起酸素(1Δg)濃度の測定

The concentration of excited oxygen (1Δg) generated by microwave discharge in a pure oxygen flow has been measured from the intensity of spontaneous emission. The conversion factor to density was determined from spectroscopic analysis of the rotational structure and calibration of the emission intensity using a black-body furnace as light source. Good agreement was found between the observed profiles and those calculated from spectroscopic data, and it was shown that the absolute concentration is obtainable by coupling band analysis and the calibration method. The concentration of excited oxygen at the microwave discharge cavity was estimated to be around 1% in the pressure range from 0.5 torr to 2 torr. Also, the comparison of the profiles calculated at different temperatures showed that the band profile can be a good indicator of gas temperature when the signal-to-noise ratio is high.