Electrical Characteristics, Plasma parameters and Reaction Rates of DC O2 Plasma

Abstract

The electrical characteristics of DC oxygen (O2) plasma such as discharge current-voltage (I-V) curves and breakdown voltage of oxygen gas were measured. The plasma parameters such as electron temperature (Te) and density (ne) were obtained using Langmuir probe at constant power over a wide range of O2 gas pressures. The measured Te values used to calculate the various rate coefficients for electron impact (ionization, dissociation and excitation) from ground state of O2 molecules. Thereafter, the calculated rate coefficients and the measured ne were used to calculate the rates of ionization, dissociation and excitation from ground state of O2 molecules. The I-V measurements of the discharge and Paschen curve show that the operating voltage was decreased with increasing O2 gas pressures at constant current and the minimum of Paschen curve was found to be 400 V at Pd = 1.86 mbar.cm, respectively. The Te showing decreasing trend with increasing O2 gas pressures while ne showing increasing trend. The rate coefficients of ionization, dissociation and excitation were found to decrease with increasing O2 gas pressure. Contrary, the rates of ionization, dissociation and excitation were found to increase with increasing O2 gas pressure.