Effect of Dilute Oxygen on Mobility of Positive Ions in Nitrogen

In order to clarify the positive ion mobility in nitrogen (N 2 ) containing tiny amounts of oxygen (O 2 ), experimental measurements were carried out for further analysis. A closed testing box including coaxial cylindrical electrodes with different parameters was built up. Under the same temperature and humidity conditions inside the box, DC positive corona was applied to produce the positive ions. The voltage and current values were recorded with different O 2 concentration in high purity N 2 , then the analytical calculation of positive ion mobility was carried out based on the classic fluid model. The mobilities under different O 2 concentration were compared and analyzed. It is found that all the mobilities of positive ions with different electrodes in N 2 decreases when the O2 concentration decreases from about 2.1% to 0.9%. The results show that the mobility of positive ions in N 2 is increased with the O 2 concentration increased, so the presence of dilute O 2 will accelerate the movement rate of positive ions in N 2 . The results can provide a reference for analyzing the ion migration process in N 2 containing dilute O2, as found in corona and streamer discharges.