Investigation on characteristics of argon corona discharge under atmospheric pressure

Spatially two-dimensional and axial-symmetric plasma model is developed to investigate the characteristics of a bar-plate corona discharge of argon gas under atmospheric pressure. An improved nonlocal collision-less electron heat flux is used in the model. Numerical simulation for the process of argon corona discharge under atmospheric pressure are carried out with a separation of 0.2 mm between the bar and plate and the discharge is excited by an external circuit. The results indicate that metastable argon atoms are mainly produced by ground state excitation reaction, the metastable step-wise ionization is the dominated reaction and the highest contribution to electron production during the discharge. In addition, the maximum of electron temperature arises in the cathode sheath due to Joule heating in the high electric field. Elastic collision is the dominant volumetric electron energy loss in atmosphere corona discharge, which is negligible in low pressure glow discharge. The discharge current-voltage characteristic is predicted and shows a good agreement with the results obtained by experiments.