Determination of Electron Density and Attenuation of Electromagnetic Waves in Ar DBD Plasmas

Prediction of electron density is crucial to numerically evaluate the attenuation of electromagnetic waves in plasmas and to optimize the parameters. In this paper, a simple collisional-radiative model (CRM) to determine the electron density of Ar dielectric barrier discharge (DBD) plasmas for pressures ranging from 0.2 to 1 atm is introduced, and then, the attenuation of electromagnetic waves is analyzed. First, the radial average electron density of Ar DBD plasma is estimated by combining the measured current and a 1-D self-consist fluid numeric model. Second, based on a simple CRM, an optical emission spectroscopy method is used to determine the radial electron density distribution. Finally, according to the radial electron density distribution, the attenuation of electromagnetic waves is calculated at a frequency range from 10 MHz to 10 GHz. The result indicates that the electromagnetic waves with a relatively low frequency can be effectively attenuated by the plasma and the edge distribution of the plasma clearly affects the attenuation.