Optical and electrical diagnostics of an atmospheric pressure room-temperature plasma plume

Abstract

Cold plasmas have recently received great attention. In this paper, optical and electrical diagnostics are carried out on a reliable and user-friendly plasma plume. A simple electrical model is used to simulate the electrical characteristics of the device. The plasma is represented by a resistor connected in parallel with a capacitor, an inductor, and another resistor, which are connected in series. The simulated current-voltage waveforms have very good agreement with experimental measurements. Besides, the emission spectra of the plasma are also studied. It shows that, when Ar is used as working gas, there is strong OH (hydroxyl radical) emission and the emission intensities of the N2 emission bands are more than three times higher than that of He. On the contrary, when He is used as working gas, the emission intensities of N2+ band are much stronger. Detail analyses on these observations are presented.