Time Evolution of Plasma Impedance Estimated From Plasma Potential and Current in Atmospheric Pressure Plasma Jet

Abstract

The potential and current of the plasma bullet are estimated from the difference in applied voltage and power-line current with and without plasma on time evolution in the atmospheric pressure plasma jet. The plasma impedance is derived by dividing the plasma potential by the plasma current. Because the time variations of the plasma potential and current differ, it is difficult to derive the time-varying phase difference. The plasma inductance is derived from the plasma potential and the time derivative of the plasma current. The plasma capacitance is derived from the plasma potential and the time integral of the plasma current, which represents plasma charge. The plasma impedance represents a capacitive load in the first half of plasma generation over time and an inductive load in the second half with the plasma bullet traveling. Consequently, when the plasma impedance is at its minimum, the reactance component is canceled out and the plasma impedance is equal to the resistance of the plasma.