Study of properties of CO2 laser mixture

Abstract

The positive column of DC glow discharge sustained in CO2 mixture (containing CO2, N2 and He) has been studied in pressure range (300÷1400) Pa and for discharge currents up to 40 mA. Parameters of discharge — electrical field strength and emission spectra — have been studied by means of double-probe method and optical emission spectroscopy. Optical scanner of original construction that enables us to study radial variations of intensities of emission lines and bands has been used for the collection of emission spectra. We have focused on the investigation of intensities of spectral bands of the second positive system of molecular nitrogen corresponding to the transition N2(C)→N2(B) in the presented paper. It has been found that shapes of radial profiles of studied bands are independent on pressure and discharge current, despite the fact that intensity of N2(C) bands decreases with increasing pressure and with decreasing current. It has also been possible to estimate vibrational temperatureTvib from measured intensities of N2(C) bands. It was observed thatTvib stays almost constant in the radial direction under our experimental conditions, but it increases with increasing discharge current and slightly decreases with increasing pressure.