Study On Characteristics Of Dual-source Excited Dielectric Barrier Discharge Plasma

Dielectric barrier discharge is a kind of discharge mode which can generate stable and relatively uniform plasma under atmospheric pressure.It has a wide range of applications in surface modification,thin film deposition,ion etching and other industrial fields.Dielectric barrier discharge is to add insulation medium between the electrodes,and the applied voltage must be AC power.When power-frequency source drives dielectric barrier discharge,the input power to the reactor is small at high voltage,and the discharge effect is not good;when the high frequency AC power source drives dielectric barrier discharge,the energy input into the reactor is very high.However,a large part of the input energy is converted into heat energy and light energy,so the energy utilization efficiency is not high.Dual-source DBD plasma are widely used in the field of microelectronics,in which high frequency power can be used to increase the number of discharges to increase the ion density,and the low frequency power supply increase the discharge power by improving the total voltage amplitude.In this paper,a dual-source excited DBD(DS-DBD)plasma source is used to excite a dielectric barrier discharge reactor using an power-frequency AC power source and a high-frequency AC power source,so that the dual-source excited DBD plasma is generated under atmospheric pressure,and the power injection power of the power frequency power source is small and the power consumption of the high-frequency power is high and a better plasma source excited dielectric barrier discharge reactor is realized.This paper mainly studies the advantages of dual-source power supply compared to single-power-frequency and single-high-frequency power supply,the influence of power-frequency and high-frequency power supply voltage amplitude on dual-source power supply,and the influence of voltage amplitude ratio of high-frequency power supply and power-frequency power supply on dual-source power supply.Simulation study of dual-source power supply and the study of dielectric barrier discharge uniformity excited by dual-source power supply in argon gas at atmospheric pressure.The main research and results obtained are as follows:(1)The single-high frequency,single-power-frequency and dual-source dielectric barrier discharges are studied.The effects of high power frequency,voltage ratio,power frequency,and high-frequency power supply voltage amplitude on dual-source power supply are studied.The results show that from the discharge image,the voltage and current waveforms and the intensity of the emission spectrum,it can be seen that under the same voltage,the high-frequency power supply is more intense than the power frequency,the high frequency discharge power increases exponentially,and the power frequency discharge power increases linearly;The dual-source discharge can promote the power frequency power supply and the high frequency power supply.The higher the ratio of the high frequency in the dual-source DBD plasma source,the closer to the high frequency mode is the discharge,and vice versa.The power-frequency has smaller contribution to dual-source power source,and the voltage amplitude change has little effect on it,while the high frequency power source has a large contribution and influence on the dual-source DBD plasma source;a high-voltage high frequency power source and a low voltage power-frequency power supply discharge phenomenon is obviously better;(2)Simulation of dielectric barrier discharges with dual-source power supply using a Comsol plasma one-dimensional simulation model.The results show: when add power-frequency voltage to high-frequency voltage,it can be easier to discharge,and electron density increase obviously.The character of dual-source DBD plasma is more like high-frequency capacitive coupling plasma,and the number of discharges per unit time is higher to power-frequency capacitive coupling plasma.In terms of the amount of active substances,the dual-source can effectively improve the production of active substances compared with the single high-frequency capacitive coupling power supply;(3)The effects of single high-frequency power supply and dual-source power supply on the uniformity of DBD in argon at atmospheric pressure were investigated from the aspects of electrical parameters,air gap spacing and carrier gas flow rate,and the conditions were optimized.The results show that the increase of the applied voltage amplitude and discharge frequency significantly improves the discharge power and the vibration temperature of the argon DBD at atmospheric pressure.In view of the uniformity of the discharge,the optimized air gap spacing is 1.3 mm.The brightness and area of dual-source power supply under flow is higher than that of single high-frequency discharge.With the increase of the carrier gas flow,the discharge area gradually expands to the downstream of the airflow,and the vibration temperature of the gas decreases.