Influences of gas flowing on the features of a helium radio-frequency atmospheric-pressure glow discharge

In this paper, a zoning model is employed to investigate the influences of gas flowing on the characteristics of the high-purity helium radio-frequency atmospheric-pressure glow discharge (RF APGD) plasma. The modeling results show that the influences of the gas flowing on the plasma features in the discharge region and the jet region are different. In the discharge region, the heavy-particle temperature decreases with the increase of helium flow rate, while the variations of the electron energy and the species concentrations are less than 0.5%. In the plasma jet region, the variation of the heavy-particle temperature shows a non-monotonous form with the gas flow rate, while the species concentrations become higher within a certain distance (e.g., smaller than 2 mm away from the plasma generator exit) at a higher helium flow rate. The modeling results are also qualitatively validated by comparing with the measured gas temperatures in both the discharge region and the plasma jet region.