Study of Non-Thermal DC Arc Plasma of CH sub(4)/Ar at Atmospheric Pressure Using Optical Emission Spectroscopy and Mass Spectrometry

• Published in: Plasma science & technology Vol. 17; no. 9; pp. 743 - 748
• Main Authors: Mengran, Liao, Yu, Wang, Hanfeng, Wu, Hui, Li, Weidong, Xia
• Format: Journal Article
• Language: English
• Published: 01.09.2015
• Subjects: Electron density; Excitation; Gas temperature; Hydrocarbons; Mass spectrometry; Optical emission spectroscopy; Spectra; Unsaturated
• ISSN: 1009-0630
• DOI: 10.1088/1009-0630/17/9/05

Non-thermal C/H/Ar plasmas are widely applied to carbonaceous material production and processing. In this work, plasma parameters and gaseous species of the atmospheric non-thermal C/H/Ar plasmas produced by an atmospheric-pressure DC arc discharge generator in CH sub(4)/Ar were investigated. The voltage-current characteristics were measured for different CH sub(4)/Ar ratios. Optical emission spectroscopy was employed to analyze the electron excitation temperature, gas temperature and electron density under various discharge conditions. The hydrocarbon molecules produced in the CH sub(4)/Ar plasmas were detected with photoionization mass spectrometry. The optical spectral results demonstrated that the electron excitation temperature was 0.4-1 eV, the gas temperature was 2800-4200 K and the electron density was in the range of (5-20)10 super(15) cm super(-3). The mass spectrum indicated that a variety of unsaturated hydrocarbons (C sub(2)H sub(4), C sub(3)H sub(6), C sub(6)H sub(6), etc.) and several highly unsaturated hydrocarbons (C sub(4)H sub(2), C sub(5)H sub(6), etc.) were produced in the non-thermal arc plasmas.