Characterization of atmospheric pressure H2O/O2 gliding arc plasma for the production of OH and O radicals

TL;DR

This study investigates the properties of atmospheric pressure H2O/O2 plasma generated by an AC power supply, analyzing temperatures and electron density variations to understand plasma behavior for potential applications.

Contribution

It provides a detailed characterization of H2O/O2 plasma properties using optical emission spectroscopy, including temperature and electron density measurements under various conditions.

Findings

Rotational and vibrational temperatures decrease with electrode spacing and O2 flow rate.

Excitation temperature increases with applied voltage and O2 flow rate.

Electron density increases with applied voltage and decreases with electrode spacing and O2 flow rate.

Abstract

Atmospheric pressure steam/oxygen plasma is generated by a 88 Hz, 6kV AC power supply. The properties of the produced plasma are investigated by optical emission spectroscopy (OES). The relative intensity, rotational, vibrational, excitation temperatures and electron density are studied as function of applied voltage, electrode spacing and oxygen flow rate. The rotational and vibrational temperatures are determined simulating the bands with the aid of LIFBASE simulation software. The excitation temperature is obtained from the CuI transition taking non-thermal equilibrium condition into account employing intensity ratio method. The electron density is approximated from the H_{\alpha} Stark broadening using the Voigt profile fitting method. It is observed that the rotational and vibrational temperatures are decreased with increasing electrode spacing and O2 flow rate, but increased with the applied voltage. The excitation temperature is found to increase with increasing applied voltage and O2 flow rate, but decrease with electrode spacing. The electron density is increased with increasing applied voltage while it seems to downward trend with increasing electrode spacing and O2 flow rate.