Study of DC Ar–CO2 mixture plasma using optical emission spectroscopy and mass spectrometry techniques

Abstract

DC generated Ar–CO2 discharge for plasma mixtures at 2.0 Torr is investigated to evaluate the variation in the electron temperature and density, electron energy distribution function, and population densities of the reactive atomic, molecular, and ionic species of CO2–Ar plasmas as a function of the Ar percentage in the mixtures. Optical emission spectroscopy and quadrupole mass spectrometry are used to determine the reactive species in the Ar–CO2 plasma in the DC discharge mode as a function of the Ar percentage. The species observed in the plasma mixtures were CO2, O2, CO, O, C2, and Ar, which agree very well with the mass spectroscopy observation. In addition, single Langmuir probes are employed to characterize the plasma. The CO species are observed to increase to 40% Ar in the mixture and then decrease. The electron temperatures and density are found to be between 1.9-3.1 eV and (0.8–2.0) × 1010 cm−3, respectively.