Study on the Differences between Atmospheric Pressure Dielectric Barrier Discharge in Oxygen and Nitrogen Gas

Based on COMSOL Multiphysics, dielectric barrier DISCHARGE (DBD) at atmospheric pressure in nitrogen and oxygen environment was investigated in detail. Due to the geometric symmetry of discharge, a one-dimensional model was introduced to simplify the simulation process. The results showed that compared with nitrogen, the discharge current in oxygen displayed more symmetric waveform, which indicated simultaneous existence of positive ions and negative ions owing to the gas electronegativity. And at the maximal discharge current, there are obvious minimum point of electrical field curve in oxygen discharge, owing to the density difference of positive and negative ions at different position of discharge gap. It also proves that the gas electronegative could lead to greater electron density gradients, higher discharge power and less uniform discharge. The electrical field curve at the moment of maximal current is selected as the characteristic parameter to distinguish gas property, electropositivity or electronegativity gas. The electrical field appear a minimum point in discharge gap, presented the shape of letter V, in electronegative gas discharge. According the mentioned characteristic curve, it is useful to determine the electronegativity of working gas.