Characterization of direct current He-N2 mixture plasma using optical emission spectroscopy and mass spectrometry

This study analyses the glow discharge of He and N2 mixture at the pressure of 2.0 Torr, power of 10 W, and flow rate of 16.5 l/min, by using optical emission spectroscopy and mass spectrometry. The emission bands were measured in the wavelength range of 200–1100 nm. The principal species observed were N2+ (B2Σ+u→X2Σ+g), N2 (C3Πu→B3Πg), and He, which are in good agreement with the results of mass spectrometry. Besides, the electron temperature and ion density were determined by using a double Langmuir probe. Results indicate that the electron temperature is in the range of 1.55–2.93 eV, and the electron concentration is of the order of 1010 cm−3. The experimental results of electron temperature and ion density for pure N2 and pure He are in good agreement with the values reported in the literature