Energetic characteristics of oxygen plasma

A low-temperature oxygen plasma is studied using the thermocouple, probe and spectral method in the range of 2-8 Torr pressure, 30-100 mA discharge currents, 0, 5, 10 m/s pumping velocity. The gas temperature, concentrations of electrons and oxygen atoms in the 3p5P state, and the longitudinal electric field are measured. Radial distributions of gas temperature and electron concentration are obtained. Ranges of pressures and currents are found in which considerable increases in electric field, discharge voltage, temperatures of gas and electrons are observed at pumping switched on. An estimate of the rate constant of the steplike ionization through the O2(a1Δg) state is given. The concentration of atomic oxygen in the ground state and excitation constant of the triplet O(3p5P) by electron impact are obtained from the solution of the balance equations and our experimental data. (orig.)