The Interaction Of Plane Electromagnetic Wave With One Dimensional Strongly Collisional And Weakly Ionized Plasmas

The Interaction of electromagnetic waves with plasmas, especially the reflection and absorption of electromagnetic waves in plasmas, is always an active research subject, important to both plasma physics and electromagnetic wave theory. Since plasmas of different configuration and density have different response characteristics, it is of great importance to investigate the influences of various plasmas to high frequency electromagnetic waves. In recent years, this field has attracted many attentions due to potential applications in wireless space communications, plasma antenna technology, and so on.The reflection and attenuation of plane electromagnetic waves propagating in the one dimensional nonuniform atmosphere pressure plasma layers, either unmagnetized or magnetized and covering a metal surface, is discussed in this thesis. Considering the effect of negative ions in the realistic atmosphere condition, the plasma composed of electrons, and positive and negative ions is assumed. In this thesis, the hyperbolic tangent ramp of the plasma density is applied at the atmosphere-plasma interface. The effects of the magnetic field, electron-neutral collision frequency, electron density gradien??lectron proportion, and plasma layer thickness on the propagation characteristic are studied with finite-difference-time-domain (FDTD) method.It is found that, for a given incident wave frequency range, in the lower frequency regime, the larger the density gradient is, the larger the reflection shall be; while it is the opposite basically in the higher wave frequency regime; the higher the electro-neutral collision frequency, the larger the electron proportion, and the thicker the plasma layer, the broader the attenuation bandwidth and the weaker the reflection. The application of the external magnetic field can enhance the attenuation band of the electromagnetic wave to a certain extent.It is shown that, the reflection and attenuation are influenced greatly by various plasma parameters and the magnetic field. It is also found that low reflection or high absorption can be reached by properly choosing magnetic field, electron-neutral collision frequency, high electron proportion, thick plasma layer, and smooth density gradient in the low frequency regime, but sharp density gradient in the high frequency regime.