Effect of pressure on the properties and species production in gliding arc Ar, O2, and air discharge plasmas

Abstract

A gliding arc discharge (GAD) plasma is generated inside a vacuum chamber with Ar, O2, and air at pressure 100–600 Torr driven by a 1 kHz, 3–6 kV power supply. The properties of the GAD plasma are investigated by electrical and optical emission spectroscopy methods. The power dissipation, relative intensity, jet length, rotational ( Tr) and excitational (Tex) temperatures, and electron density (ne) are studied as a function of applied voltage, pressure, and feeding gas. It is found from the electrical characteristics that the power dissipation shows decreasing trends with increasing pressure but increasing with increasing voltage. The relative population densities of the reactive species N2(C−B), O, and OH radicals produced as functions of pressure and applied voltage are investigated. It is found that the relative population densities of the species, especially N2(C−B) and O, are increased with applied voltage and pressure, while OH(A-X) is decreased. The spectroscopic diagnostics reveals that Tr≈550–850 K, Tex≈8200–10 800 K, and ne≈2.65–5.3×1014 cm−3 under different experimental conditions. Tr and ne are increased with increasing pressure, while Tex is decreased.