Electromagnetic wave penetration of reentry plasma sheaths

Bachynski, M. P.

doi:10.6028/jres.069d.023

Cited by 15 publications

(11 citation statements)

References 7 publications

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“…Note that we have neglected here the electron-neutral collisions. 1 The density and velocity of the electrons are connected by the continuity equation (5) On taking the curl of (2) and inserting (1) in it, we obtain (6) where is the free space wave number. From the equation of motion, we have (7) Substituting (7) in (6), we obtain the following equation for the electromagnetic waves (8) where (9) and…”

Section: Electromagnetic Wavesmentioning

confidence: 99%

“…Such communication blackout problems are also encountered in many other space exploration missions [4]. Some of early schemes that were proposed are: use of electron beams [5], high-frequency laser [6], strong static magnetic fields [5]- [8], and alteration of chemical composition [9]- [13]. Two articles that summarize early ideas are those of Rawhouser [5] and Rybak [14].…”

Section: Introductionmentioning

confidence: 99%

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Radiation Characteristics of Antennas Embedded in a Medium With a Two-Temperature Electron Population

Mudaliar

Sotnikov

2012

IEEE Trans. Antennas Propagat.

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It is well-known that low-frequency electromagnetic (EM) signals are heavily attenuated in a medium with dense electron population. All signals below the plasma frequency of the medium get cut off. If we create in this medium, a small population of relatively hot electrons the composite medium then supports low-frequency electrostatic oscillations known as electron acoustic waves (EAW) [e.g., Gary and Tokar, Phys. Fluids 28, 2439]. The dispersion relation of this composite medium shows that it supports EAW in the frequency band where EM signals are cut off. Thus, it is possible, in principle, to employ EAW to transmit signals across an overdense plasma medium. Our primary interest in this paper is to study the radiation characteristics of a source current distribution embedded in a half-space of our composite medium. To enable this, we derive the Green's functions for our problem and, hence, study the radiation characteristics of antennas. When the source signal frequency is below the plasma frequency, only EAW exist in the composite medium, while only EM waves can exist in the free space above. We find that the far-zone radiation fields of any current distribution consist only of -polarized waves. Explicit expressions for the radiated fields are obtained for horizontally-and vertically-polarized Hertzian dipoles embedded in our composite medium. We, hence, find that in both cases the radiation patterns are skewed towards the horizon. In particular, we find that the radiation pattern of a horizontal dipole has two lobes as opposed to one in the underdense case.

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Section: Electromagnetic Wavesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Radiation Characteristics of Antennas Embedded in a Medium With a Two-Temperature Electron Population

Mudaliar

Sotnikov

2012

IEEE Trans. Antennas Propagat.

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“…The communication blackout during re-entry of a spacecraft can be alleviated in various ways as suggested by [1,[5][6][7]. Some of these methods along with their merits and demerits are discussed below: …”

Section: Mitigation Techniquesmentioning

confidence: 99%

Mitigation of Communication Blackout During Re-Entry Using Static Magnetic Field

Mehra

Singh²,

Bera³

2015

PIER B

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Abstract-During re-entry into earth's atmosphere, a spacecraft suffers from loss of communication with the ground control station, known as communication blackout, due to formation of plasma around the re-entry spacecraft. This paper presents the theory and analysis of the communication blackout and its mitigation using static magnetic field method. The interaction between electromagnetic waves and plasma in presence as well as absence of magnetic field is described to determine the effects of plasma sheath on the spacecraft re-entering into the atmosphere. An analysis is done to determine the effectiveness of this mitigation technique for a typical re-entry spacecraft and the strength of magnetic field required to establish the communication link between the re-entry spacecraft and the ground station is obtained.

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“…This phenomenon is used in various applications, including plasma density diagnostic. It presents, however, a major problem for radio communications through dense plasmas which is created around a vehicle at re-entry, or during hypersonic flight [7][8][9][10]. Characterization of reflected and absorbed electromagnetic radiation is also of great interest for radar applications [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Resonant Transparency of a Three-Layer Structure Containing the Dense Plasma Region

Sternberg¹,

Smolyakov²

2009

PIER

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Abstract-A study of electromagnetic wave propagation in dense plasmas when the wave frequency is below the cut-off frequency is presented. A three-layer symmetric structure consisting of dense plasma nested between two boundary layers is studied analytically and numerically. The permittivity of the dense plasma is negative, while the permittivity of each boundary layer is greater than 1. It is shown that total transmission of an electromagnetic wave can be achieved if an adequate incidence angle, dielectric permittivity of the boundary layers and corresponding boundary layer widths are chosen. It is found that plasma transparency is due to resonance between the evanescent waves in the dense plasma region and the standing waves in the boundary layers. Resonance conditions are derived analytically and the relationship between the corresponding parameters of the problem are studied numerically.

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Electromagnetic wave penetration of reentry plasma sheaths

Cited by 15 publications

References 7 publications

Radiation Characteristics of Antennas Embedded in a Medium With a Two-Temperature Electron Population

Radiation Characteristics of Antennas Embedded in a Medium With a Two-Temperature Electron Population

Mitigation of Communication Blackout During Re-Entry Using Static Magnetic Field

Resonant Transparency of a Three-Layer Structure Containing the Dense Plasma Region

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