A simple generator of a stationary flow of non-equilibrium atmospheric-pressure plasma

A simple design of a plasma discharge set up, providing a stationary flow of non-equilibrium atmospheric-pressure plasma is proposed. The non-equilibrium state of plasma is maintained by using a cathode with a weakly conducting liquid like tap water. The anode is formed with a cooled metal ring-shaped inserted in a dielectric barrel. This assembly is fixed at ∼ 1 cm above the water surface. The velocity of the air flow through the anode hole may be changed from 0 m/s up to ∼ 10 m/s. The studied discharge in the open air gap between the tap water surface and the anode ring is powered by direct current I ∼ 0.1 A. The voltage on the air gap is ≥ 1 kV. Measurements of current-voltage characteristics at different flow velocities were carried out. Spectra of radiation of the discharge column and the torch above the anode were measured. The measurement results were compared with the results of radiation spectra modeling for non-equilibrium plasma of humid air. The comparison made possible to determine the characteristics of plasma. The characteristics of the plasma depending on the speed of the airflow and the current are studied.