基于印刷电路板的沿面型介质阻挡放电特性

Surface dielectric barrier discharge (SDBD) generating the atmospheric pressure low temperature plasma has broad application prospects in several fields including the biomedicine. In this paper, a SDBD device based on a printed circuit board (PCB) is used and its electrical and optical characteristics including the uniformity, discharge mode and pattern, discharge power together with plasma emission spectra are investigated when the device is driven by a sinusoidal AC power supply. The results show that the discharge intensity and uniformity increase with the raised voltage amplitude and frequency. When the peak-to-peak value of applied voltage is higher than 5.2 kV, the macroscopic stable and uniform discharge will appear. The surface discharge develops into a dispersive discharge inside the grid from the contraction discharge at the three junction points including the fine line edge of the lattice, dielectric material and air. Besides, the discharge intensity during positive half cycle of voltage is stronger than that in the case of negative half cycle, which is mainly caused by the difference of the inhibition of the electric field along the surface by the surface charges in the positive and negative discharges. When the applied voltage amplitude ranges from 5.0 kV to 6.2 kV, due to the enhanced electric field intensity and collision frequency between particles, the energy is injected into the discharge space, and the number of high-energy electrons and the particle kinetic energy are strengthened. As a result, the discharge becomes stronger, which ultimately enables the discharge power of SDBD device, the relative intensity of plasma emission spectra, the vibration and rotation temperature of nitrogen molecules to increase to various degrees with the increasing voltage amplitude.