Influence of impurities on the temperature of an atmospheric helium plasma in microwave resonant cavity

Abstract

The influence of the content and nature of impurities on the rotational temperature of three probe molecules (OH, NH and ) in a helium plasma created in a microwave resonant cavity is investigated by the synthetic spectra method and by mass spectrometry. OH is found to be the only reliable probe to obtain a satisfactory estimation of the gas temperature. In our experimental conditions, depending on the impurity, the gas temperature varies strongly and at 500 ppm, for instance, a difference of 700 K is possible (∼30% of the mean temperature).

Microwave Plasma Jet in Water: Characterization and Feasibility to Wastewater Treatment

“…To estimate the rotational temperature of plasma particles (Trot), we use the measured OH spectra by adopting the fitting method developed by Rodrigo et al [29], and the results are shown in figures 6a and b. As a result, we find that the temperature increases from ~1300 to ~3200 K as the μWP increases from 25 to 200 W (figure 6c).…”

Electrical, Thermal and Optical Parametric Study of Guided Ionization Waves Produced with a Compact μs-Pulsed DBD-Based Reactor

“…In our case, OH(A-X) emission was detected in the emission spectrum of GIWs (see Figure 11). A representative experimental rotational structure of this molecule is given in Figure 13 (black color), which was fitted with the corresponding synthetic rotational spectrum (red dots) that was produced with a home-made code [6,14,15,51]. T rot was obtained as the value giving the best fit between these two spectra based on the least squares method.…”

Dielectric barrier discharge plasma used as a means for the remediation of soils contaminated by non-aqueous phase liquids

“…The gas temperature was estimated by recording the rotational distributions of selected bands of the Second Positive System (SPS) of the N 2 molecules and fitting on them the theoretical distributions corresponding to different temperatures by means of homedeveloped software [39]. Moreover, the temperature on the grounded grid was recorded in real-time by attaching a thermocouple (K-type) on its rear surface and reading the data with a data logger.…”