Comparison of Vibrational-Rotational Temperature and Excitation Temperature in Ar-Molecular Gas Induction Thermal Plasmas

The carbon dioxide gas was injected into Ar induction thermal plasmas to investigate the plasma-quenching efficiency of CO2 and N2. In the experiments, C2 molecular band spectra and N2+ molecular spectra were found. Theoretical calculation of the radiation intensity for C2 Swan system and N2+ first negative system was carried out as functions of excitation temperature, rotational temperature and vibrational temperature. The fitting technique between the experimental and theoretical radiation intensities of the C2 Swan spectra and N2+ spectra was used for determination of rotational and vibrational temperatures. It was found that vibrational temperature was decreased with increasing CO2 admixture ratio into Ar thermal plasmas, which may be related with a decreased electron temperature.