Simulation of dual-frequency dielectric barrier discharge at atmospheric pressure

To understand the mechanism of plasma discharge in argon dual-frequency (DF) dielectric barrier discharge (DBD), a two-dimensional symmetric fluid model is established and numerically simulated by the finite element method. The low-frequency excitation source is 500kHz, and the amplitude is fixed at 750V cosine voltage. The RF frequency is 100MHz sinusoidal voltage. The discharge characteristics of plasma under different RF voltages are discussed. At U<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RF</inf>=0V, the LF discharge current contains two peaks in each LF cycle, while at DF discharge (U<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">RF</inf> > 0V), the current is a superposition of the LF and RF components. With the increase of the RF voltage amplitude, the electric field and electron density in the discharge gap are more widely distributed, the plasma density increases, and the plasma discharge in the reactor is more uniform. This study contributes to a more specific understanding of the behavior of plasma in DF-DBD reactors.