Title: Electrical Characteristics, Plasma parameters and Reaction Rates of DC O2 Plasma
Abstract: The electrical characteristics of DC oxygen(O 2 ) plasma such as the discharge current-voltage (I-V) curves and the breakdown voltage of oxygen gas were measured.The plasma parameters such as electron temperature (T e ) and density (n e ) were obtained using Langmuir probe at a constant power over a wide rangeof O 2 gas pressures.The measured T e values were used to calculate the various rate coefficients for electron impact (ionization, dissociation and excitation) from ground state of O 2 molecules.Thereafter, the calculated rate coefficients and the measured n e values were used to calculate the rates of ionization, dissociation and excitation from ground state of O 2 molecules.The I-V measurements of the discharge and Paschen curve show that the operating voltage decreased with increasing O 2 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 T e showed a decreasing trend with increasing O 2 gas pressures while n e showed an increasing trend.The rate coefficients of ionization, dissociation and excitation were found to decrease with increasing O 2 gas pressure.On the contrary, the rates of ionization, dissociation and excitation were found to increase with increasing O 2 gas pressure.