Dependence of plasma current on object condition in atmospheric pressure non-thermal equilibrium argon plasma

The dependence of the plasma plume current on the object condition is investigated by atmospheric pressure non-thermal equilibrium argon plasma. When processing with plasma, the flow of plasma current changes depending on the condition of the object. In the case of metal object with grounded condition, the plasma current was independent of the surface area and electrical conductivity of the metal object. While, in the case of metal object with floating condition, the plasma current was dependent on the surface area of the metal object, but not on the electrical conductivity of the metal object. When an object is grounded, the closed circuit is fixed with plasma, object, and ground-line, and then the current flow follows Ohm’s law. Because the ground-line is longer than the plasma plume length and the scale length of the object, the plasma current is independent of the characteristics of the metal object. When the object is in a floating condition, the divergence of the charge stored in the object to the atmosphere depends on the surface area of the object because it follows Gauss’s law.