大气压脉冲调制射频氩气放电等离子体特性的数值研究

Numerical study on pulse modulated RF argon discharge at atmospheric pressure

基于等离子体流体理论,建立了大气压脉冲调制射频氩气放电的一维流体模型。通过数值模拟的方法研究了放电参数(放电电极间距、射频频率)对氩等离子体特性的影响。研究结果表明:当电压固定时,随着电极间距的增加,等离子体区逐渐增大,最大电子密度也增加,在0.20cm达到最大值后略有降低;放电电流密度与输入功率密度随着电极间距的增加而增加;鞘层区电子温度随着电极间距的增加而降低;在脉冲开启前期,等离子体区电子温度随着电极间距的增加而增加,但当脉冲开启后期,电极间距对等离子体区电子温度影响较小。不同射频频率下最大电子密度随电极间隙的增加而减小,也具有一个最优值。

Based on plasma fluid theory, a one-dimensional fluid model of atmospheric pressure pulse modulated radio frequency(RF) argon discharge is established. The effects of discharge parameters(discharge gap, radio frequency) on argon discharge characteristics are studied by numerical simulation. The results show that the plasma density increases first and then drops as the electrode gap increases when the applied voltage is fixed, and it has an optimal value. As the electrode gap keeps increasing, the discharge current density and input power density increase, and the electron temperature decreases in the sheath region while it increases in the plasma region during the early time of the pulse while the electrode gap has little effect on electron temperature during the later time of the pulse. The maximum electron density decreases with electrode gap increase at the different frequency, and it has an optimal value.