Abstract
Propagation characteristics of electromagnetic (EM) waves in partially ionized plasma slabs are studied in this paper. Such features are significant to applications in plasma antennas, blackout of re-entry flying vehicles, wave energy injection to plasmas, and etc. We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas. Particularly, the EM wave propagation in sub-wavelength plasma slabs, where the geometric optics approximation fails, is studied and in comparison with thicker slabs where the geometric optics approximation applies. The influences of both plasma and collisional frequencies, as well as the width of the plasma slab, on the EM wave propagation characteristics are discussed. The results can help the further understanding of propagation behaviours of EM waves in nonuniform plasma, and applications of the interactions between EM waves and plasmas.
Highlights
We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas
The propagation characteristics of EM waves propagating vertically to a partially ionized nonuniform plasma slab are investigated by a theoretical model solved by a differential thin layer method numerically in this paper
(2) In the weak collision regime, the EM wave amplitude amplitude of the EM wave (AEM) falls rapidly when the plasma density goes beyond the level of the critical density
Summary
Ionized plasma layers are commonly formed in many artificially applied or naturally generated processes, such as plasma antennas, reentry plasma sheaths of spacecraft, and etc.[1,2] Characterized by non-uniformity of plasma distributions, a high number density of neutral particles, a broad frequency range of electron-neutral collisions, the partially ionized plasma slabs have been studied extensively, for radio-frequency (rf) wave communication and control, material processing, and other applications.[3,4,5,6,7,8,9,10] Especially, the interaction between partially ionized plasmas and electromagnetic (EM) waves becomes a key issue in the fundamental studies, and in the practical applications.[11,12,13] Take communication and control during spacecraft reentry for example, as to the case with a highly nonuniform plasma layer covering the vehicle, understanding of the interaction between EM waves and such typical plasmas is crucial to performance reliable communication, and extensively investigated. The width of blackout plasma sheaths covering the flying vehicle is usually on the same order of or even shorter than the wavelength of rf waves applied In this case the rf EM waves propagate in a sub-wavelength regime, where the propagation characteristics should be significantly different from that in the geometric optics regime.[19] WKB methods used previously for EM wave propagations in plasma layers[20,21] are not applicable for such cases. Guided by previous researches and taking the sub-wavelength property into account, we in this paper develop a physical model and corresponding differential thin layer method to investigate the EM wave propagation characteristics in nonuniform sub-wavelength plasma slabs with a broad range of collision frequencies.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
