Excitation of electromagnetic waves by delta function current sheets in the ionospheric plasma

Radio Science ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 867-877 ◽  
Author(s):  
Mahmoud Omid ◽  
Masashi Hayakawa
Keyword(s):  
Electromagnetic Waves ◽  
Ionospheric Plasma ◽  
Delta Function ◽  
Current Sheets

scholarly journals Electromagnetic Waves Through Disordered Systems: Comparison of Intensity, Transmission and Conductance

2001 ◽  
Vol 694 ◽  
Author(s):  
Fredy R Zypman ◽  
Gabriel Cwilich
Keyword(s):  
Probability Distribution ◽  
Disordered Systems ◽  
Electromagnetic Waves ◽  
Delta Function ◽  
Rayleigh Distribution ◽  
Dirac Delta Function ◽  
Universal Form ◽  
Dirac Delta ◽  
Diffusive Regime ◽  
Analytical Expressions

AbstractWe obtain the statistics of the intensity, transmission and conductance for scalar electromagnetic waves propagating through a disordered collection of scatterers. Our results show that the probability distribution for these quantities x, follow a universal form, YU(x) = xne−xμ. This family of functions includes the Rayleigh distribution (when α=0, μ=1) and the Dirac delta function (α →+ ∞), which are the expressions for intensity and transmission in the diffusive regime neglecting correlations. Finally, we find simple analytical expressions for the nth moment of the distributions and for to the ratio of the moments of the intensity and transmission, which generalizes the n! result valid in the previous case.

A Simple Approach to Evaluate Near Field Thermal Radiation From Emitters With Layered Structures and Temperature Variations in One Direction

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Sy-Bor Wen
Keyword(s):  
Analytical Solutions ◽  
Electromagnetic Waves ◽  
Near Field ◽  
Layered Structures ◽  
Calculation Scheme ◽  
Temperature Variations ◽  
Current Sheets ◽  
Infinite Domains ◽  
Thermal Current ◽  
Field Radiation

Abstract A simple analytical calculation scheme to determine near field radiation through decomposing an emission domain into lots of thin thermal current sheets is presented. Through finding the orthogonal modes of thermal current of each thin layer, the thin current sheets can be treated as radiation sources of electromagnetic waves with determined analytical solutions. The outgoing electromagnetic waves from each thin current sheets can be either in transverse electric (TE) or transverse magnetic (TM) modes depending on the orientations of the current in the thin current sheets with respect to the directions of amplitude modulations of the orthogonal modes. Electromagnetic waves arriving to a collection domain are related to the electromagnetic waves leaving from each thin current thermal sheet with transfer coefficients. Transfer coefficient for TE and TM waves can be determined analytically with transfer matrix method or scattering matrix methods. Compared with existing dyadic Green's function method, the new calculation scheme allows material and temperature variations along one direction of the emission domain based on determined analytical expressions of TE and TM waves leaving from each thin current sheets. The simple calculation scheme is especially useful in near field radiation of layered structures with different material such as hyperbolic material with negative refractive indices. With this new approach, we recovered analytical solutions of near field radiation between two semi-infinite domains with uniform temperature and derived closed form solution of near field radiation between two semi-infinite domains with temperature profiles with/without laminated structures.

scholarly journals Excitation of VLF quasi-electrostatic oscillations in the ionospheric plasma

1996 ◽  
Vol 14 (1) ◽  
pp. 27-32 ◽  
Author(s):  
B. Lundin ◽  
C. Krafft ◽  
G. Matthieussent ◽  
F. Jiricek ◽  
J. Shmilauer ◽  
...  
Keyword(s):  
Heat Flux ◽  
Electromagnetic Waves ◽  
Ionospheric Plasma ◽  
Electron Distribution Function ◽  
Collisionless Plasma ◽  
Sound Waves ◽  
Thermal Electron ◽  
Band Emission ◽  
Suprathermal Electrons ◽  
A Current

Abstract. A numerical solution of the dispersion equation for electromagnetic waves in a hot magnetized collisionless plasma has shown that, in a current-free ionospheric plasma, the distortion of the electron distribution function reproducing the downward flow of a thermal electron component and the compensating upward flow of the suprathermal electrons, which are responsible for the resulting heat flux, can destabilize quasi-electrostatic ion sound waves. The numerical analysis, performed with ion densities and electron temperature taken from the data recorded by the Interkosmos-24 (IK-24, Aktivny) satellite, is compared with a VLF spectrum registered at the same time on board. This spectrum shows a wide frequency band emission below the local ion plasma frequency. The direction of the electron heat flux inherent to the assumed model of VLF emission generation is discussed

Collisionless damping of ordinary electromagnetic waves in the ionospheric plasma with power spectrum of inhomogeneities

1991 ◽  
Vol 34 (3) ◽  
pp. 214-220
Author(s):  
A. G. Bronin ◽  
P. F. Denisenko ◽  
G. A. Zhbankov ◽  
N. A. Zabotin
Keyword(s):  
Power Spectrum ◽  
Electromagnetic Waves ◽  
Ionospheric Plasma

scholarly journals Evidence of <i>L</i>-mode electromagnetic wave pumping of ionospheric plasma near geomagnetic zenith

2018 ◽  
Vol 36 (1) ◽  
pp. 243-251 ◽  
Author(s):  
Thomas B. Leyser ◽  
H. Gordon James ◽  
Björn Gustavsson ◽  
Michael T. Rietveld
Keyword(s):  
Electromagnetic Waves ◽  
Ionospheric Plasma ◽  
Pump Wave ◽  
Topside Ionosphere ◽  
Mode Propagation ◽  
Pump Frequency ◽  
Density Peak ◽  
F Region ◽  
Left Handed ◽  
Magnetic Zenith

Abstract. The response of ionospheric plasma to pumping by powerful HF (high frequency) electromagnetic waves transmitted from the ground into the ionosphere is the strongest in the direction of geomagnetic zenith. We present experimental results from transmitting a left-handed circularly polarized HF beam from the EISCAT (European Incoherent SCATter association) Heating facility in magnetic zenith. The CASSIOPE (CAScade, Smallsat and IOnospheric Polar Explorer) spacecraft in the topside ionosphere above the F-region density peak detected transionospheric pump radiation, although the pump frequency was below the maximum ionospheric plasma frequency. The pump wave is deduced to arrive at CASSIOPE through L-mode propagation and associated double (O to Z, Z to O) conversion in pump-induced radio windows. L-mode propagation allows the pump wave to reach higher plasma densities and higher ionospheric altitudes than O-mode propagation so that a pump wave in the L-mode can facilitate excitation of upper hybrid phenomena localized in density depletions in a larger altitude range. L-mode propagation is therefore suggested to be important in explaining the magnetic zenith effect. Keywords. Space plasma physics (active perturbation experiments)

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