Influence of discharge parameters on electromagnetic scattering

Setting the thickness and pressure for an absorbing plasma is difficult in plasma stealth engineering. In this study we established a numerical model of electromagnetic wave propagation in radiofrequency plasma using a z-transformed, finite-difference, time-domain method. We studied the effects of thickness and pressure on the reflectance, transmittance and attenuation of the plasma under three typical electron density distributions: uniform, axially symmetric and monotonic. The results show that the electron density distribution has a significant influence on the electromagnetic wave transmission characteristics. The attenuation effect reaches a maximum when the electron density is increased monotonically along the wave propagation direction. An increase in thickness can significantly increase the attenuation rate of the incident wave and reduce the transmittance, but has little effect on the reflectance. An increase in air pressure reduces the reflectance of the incident wave and increases the transmittance and the attenuation rate. However, once the air pressure exceeds a certain threshold, any further increase in air pressure will no longer enhance the attenuation rate.