Characteristic Investigation of an Atmospheric-Pressure Microwave N2–Ar Plasma Torch

Impedance matching is implemented to stabilize an atmospheric-pressure waveguide-based N ₂ -Ar plasma torch with the aid of the use of swirl gas. Optical emission spectroscopy is employed to diagnose the plasma torch with respect to the population of the electronic state N ⁺ ₂ (B ² Σ ⁺ _u ) and N ₂ (B ³ Π _g ) versus the absorbed power and the ratio of N ₂ component in the Ar-N ₂ mixture by the measurement of the emission of intensity. The qualitative discussion based on the reaction routes is delivered to interpret the experimental results well.