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 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

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)

scholarly journals Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum

2020 ◽  
Vol 500 (1) ◽  
pp. 1232-1242
Author(s):  
Nicolas Fagnoni ◽  
Eloy de Lera Acedo ◽  
David R DeBoer ◽  
Zara Abdurashidova ◽  
James E Aguirre ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Phase I ◽  
Electromagnetic Waves ◽  
Mutual Coupling ◽  
System Response ◽  
Receiver System ◽  
Simulated System ◽  
Systematic Effects ◽  
System Time ◽  
Large Sections

ABSTRACT The detection of the Epoch of Reionization (EoR) delay power spectrum using a ‘foreground avoidance method’ highly depends on the instrument chromaticity. The systematic effects induced by the radio telescope spread the foreground signal in the delay domain, which contaminates the EoR window theoretically observable. Applied to the Hydrogen Epoch of Reionization Array (HERA), this paper combines detailed electromagnetic and electrical simulations in order to model the chromatic effects of the instrument, and quantify its frequency and time responses. In particular, the effects of the analogue receiver, transmission cables, and mutual coupling are included. These simulations are able to accurately predict the intensity of the reflections occurring in the 150-m cable which links the antenna to the backend. They also show that electromagnetic waves can propagate from one dish to another one through large sections of the array due to mutual coupling. The simulated system time response is attenuated by a factor 104 after a characteristic delay which depends on the size of the array and on the antenna position. Ultimately, the system response is attenuated by a factor 105 after 1400 ns because of the reflections in the cable, which corresponds to characterizable k∥-modes above 0.7 $h\,\,\rm {Mpc}^{-1}$ at 150 MHz. Thus, this new study shows that the detection of the EoR signal with HERA Phase I will be more challenging than expected. On the other hand, it improves our understanding of the telescope, which is essential to mitigate the instrument chromaticity.

Invariant properties of wave propagation in n-dimensional space

1976 ◽  
Vol 79 (3) ◽  
pp. 563-571 ◽  
Author(s):  
John Heading
Keyword(s):  
Wave Propagation ◽  
Differential Equations ◽  
Circular Polarization ◽  
Electromagnetic Waves ◽  
Ionospheric Plasma ◽  
Dimensional Space ◽  
Isotropic Case ◽  
Anisotropic Model ◽  
Invariant Properties

AbstractThe paper continues earlier work on the generalization in n-dimensional space of the differential equations governing the propagation of electromagnetic waves in inhomogeneous anisotropic ionospheric plasma. Here there are investigated certain properties of the equations and their solutions that are independent of the dimension n of the space in which propagation takes place. The isotropic case is discussed, together with a special anisotropic model for which the various planes of circular polarization are geometrically related to each other.

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