Electron density of kHz operated atmospheric pressure dielectric barrier discharge (APDBD) can be estimated from the V-I phase angle measurement using the proposed equivalent circuit model. The model consisted of the plasma resistance, the capacitive reactance, and the system impedance corresponding to the reactor capacitance and power line impedance. The phase difference was determined from the gap voltage (V) and the displacement current (I) flown on the equivalent circuit, applying to estimate the electron density in the reactor system. Since the V-I phase difference is a function of the ratio of plasma resistance and reactance, the spatially averaged electron density can be analyzed. Feasibility of the monitoring method was evaluated for 1 and 20 kHz APDBD plasmas using nitrogen gas. Obtained electron densities have a good agreement of 1D simulation results as 105~108 cm-3 during a half cycle period.

 10.1109/TPS.2012.2234140