Large-Area Cold Atmospheric Pressure Discharges Realized by Mesh Covered Tube-Plate Electrodes in Open Air

A large-area atmospheric pressure plasma with low temperature and high electron density was realized using mesh covered tube-plate electrodes at an RF power as low as 4 W. The gas temperature is less than 351 K, while the electron temperature is about 5000 K. The estimated electron density is on the order of 10¹² cm^-3. Electrical measurements indicate that the discharges are capacitive and operated in an abnormal glow discharge mode. In addition, a self-bias observed at the powered tube electrode increases with increasing power and is positive at high powers.