Resonant interaction of electron cyclotron waves with a plasma containing arbitrarily drifting suprathermal electrons

1985 ◽  
Vol 34 (2) ◽  
pp. 319-326 ◽  
Author(s):  
A. Orefice
Keyword(s):  
Electromagnetic Waves ◽  
Electron Distribution Function ◽  
Resonant Interaction ◽  
Electron Cyclotron ◽  
Dielectric Tensor ◽  
Suprathermal Electrons ◽  
Relativistic Treatment ◽  
Electron Cyclotron Waves ◽  
Plasma Dispersion ◽  
The Magnetic Field

A relativistic treatment of the plasma dispersion functions and of the dielectric tensor for electron cyclotron electromagnetic waves is given for non-thermal plasmas where the electron distribution function can be represented as a combination of Maxwellians with arbitrary drifts along the magnetic field.

Relativistic theory of absorption and emission of electron cyclotron waves in anisotropic plasmas

1988 ◽  
Vol 39 (1) ◽  
pp. 61-70 ◽  
Author(s):  
A. Orefice
Keyword(s):  
Relativistic Theory ◽  
Electron Distribution ◽  
Electron Distribution Function ◽  
Distribution Functions ◽  
Electron Cyclotron ◽  
Loss Cone ◽  
Absorption And Emission ◽  
Electron Cyclotron Waves ◽  
Plasma Dispersion ◽  
Weakly Relativistic Plasma

The weakly relativistic theory of absorption and emission of electron cyclotron waves in hot magnetized plasmas is developed for a large class of anisotropic electron distribution functions. The results are expressed in terms of the weakly relativistic plasma dispersion functions, and therefore of the well-known plasma Z-function. The particular case of a loss-cone electron distribution function is presented as a simple example.

Electron-cyclotron absorption by inhomogeneous current-carrying plasmas

1994 ◽  
Vol 52 (2) ◽  
pp. 195-214 ◽  
Author(s):  
C. J. H. Cavalcanti ◽  
R. S. Schneider ◽  
L. F. Ziebell
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Electron Cyclotron ◽  
Wave Frequency ◽  
Cyclotron Absorption ◽  
Homogeneous Background ◽  
Electron Cyclotron Waves ◽  
The Magnetic Field

We consider effects of inhomogeneity on the absorption of high-frequency electromagnetic waves, propagating at arbitrary angles relative to the magnetic field, by current-carrying plasmas. An inhomogeneous current is assumed to be immersed in an otherwise homogeneous background, and the absorption of fundamental electron-cyclotron waves is discussed, with emphasis on the dependence of the inhomogeneity effect on wave frequency and angle of propagation.

Relativistic dielectric tensor of a Maxwellian plasma for electron cyclotron waves at arbitrary propagation angles

1982 ◽  
Vol 27 (3) ◽  
pp. 515-524 ◽  
Author(s):  
A. C. Airoldi ◽  
A. Orefice
Keyword(s):  
Incident Angle ◽  
Electron Cyclotron ◽  
Dielectric Tensor ◽  
Maxwellian Plasma ◽  
Electron Cyclotron Waves ◽  
Arbitrary Propagation

The relativistic dielectric tensor of a magnetized Maxwellian plasma is obtained in a general way, for electron cyclotron waves at arbitrary incident angle. A new expression is provided for the computation of the relativistic (Shkarofsky) dispersion functions.

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

Weakly relativistic dielectric tensor and dispersion functions of a Maxwellian plasma

1983 ◽  
Vol 30 (1) ◽  
pp. 125-131 ◽  
Author(s):  
V. Krivenski ◽  
A. Orefice
Keyword(s):  
Magnetic Field ◽  
Wave Vector ◽  
Magnetized Plasma ◽  
Harmonic Number ◽  
Dielectric Tensor ◽  
Absorption And Emission ◽  
Emission Properties ◽  
Maxwellian Plasma ◽  
Plasma Dispersion ◽  
The Magnetic Field

In order to study the absorption and emission properties of a magnetized plasma in the electron cyclotron range of frequencies, the weakly relativistic (Shkarofsky) plasma dispersion functions are simply and exactly expressed in terms of the Z function. This gives a useful working form to the dielectric tensor, for any wave vector and harmonic number, covering also the case of electron Maxwellian distributions drifting along the magnetic field.

Alternative representation of the dielectric tensor for a relativistic magnetized plasma in thermal equilibrium

1990 ◽  
Vol 43 (2) ◽  
pp. 269-281 ◽  
Author(s):  
Peter H. Yoon ◽  
Ronald C. Davidson
Keyword(s):  
Thermal Equilibrium ◽  
Electromagnetic Waves ◽  
Dimensionless Parameter ◽  
Relativistic Effects ◽  
Magnetized Plasma ◽  
Dielectric Tensor ◽  
Alternative Representation ◽  
Formal Result ◽  
Weakly Relativistic Plasma ◽  
The Magnetic Field

An alternative representation of the dielectric tensor εij(k, ω) for a relativistic magnetized plasma in thermal equilibrium is presented. This representation involves an infinite series expansion in powers of , as well as an asymptotic expansion for large Here ωc = eB0/mc is the nonrelativistic cyclotron frequency, k⊥ is the wavenumber perpendicular to the magnetic field B0êz, and α is the dimensionless parameter defined by α = mc2/KBT. The present work generalizes Shkarofsky's (1966) representation. Moreover, unlike Trubnikov's (1958) formal result, in which the k⊥ and kz dependences of εij(k, ω) are inexorably coupled, the present representation naturally separates the k⊥ and kz dependences of εij(k, ω). As an application, the general expression is simplified for the case of a weakly relativistic plasma, and the dispersion relation is obtained for electromagnetic waves, including first-order relativistic effects. The method developed in this paper can be used for other non-thermal distributions.

Suppression of runaway electrons during electron cyclotron resonance heating on HL-2A tokamak

2009 ◽  
Vol 76 (1) ◽  
pp. 75-85 ◽  
Author(s):  
JIN-WEI YANG ◽  
YI-PO ZHANG ◽  
XU LI ◽  
XIAN-YING SONG ◽  
GUO-LIANG YUAN ◽  
...  
Keyword(s):  
Electric Field ◽  
Cyclotron Resonance ◽  
Electron Cyclotron Resonance ◽  
Resonant Interaction ◽  
Electron Cyclotron ◽  
Electron Cyclotron Resonance Heating ◽  
Runaway Electrons ◽  
Long Duration ◽  
Cross Correlation Analysis ◽  
Electron Cyclotron Waves

AbstractThe statistical analysis of heating effect and the cross-correlation analysis of both electron temperature and loop voltage have been done during electron cyclotron resonance heating (ECRH). The behavior of runaway electrons in the flat-top phase during ECRH are analyzed using experimental data. It is shown that the runaway population is indeed suppressed or even quenched when the toroidal electric field ET is reduced below the threshold electric field Eth by high-power and long-duration ECRH. The physical mechanism of runaway suppression is explored by the resonant interaction between the electron cyclotron waves and the energetic runaway electrons.

Plasma waves in the inner Jovian magnetosphere at low to mid-latitudes

2021 ◽  
Author(s):  
William Kurth ◽  
George Hospodarsky ◽  
Ali Sulaiman ◽  
Sadie Elliott ◽  
John D. Menietti ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Outer Edge ◽  
Electron Cyclotron ◽  
Magnetic Equator ◽  
Whistler Mode ◽  
Jovian Magnetosphere ◽  
Northern Latitudes ◽  
Angle Scattering ◽  
Electron Cyclotron Waves ◽  
Wave Phenomena

<p>Juno's highly eccentric polar orbit was designed to provide the first measurements at low altitudes over the poles to explore Jupiter’s polar magnetosphere and auroras.  Orbit precession moves the initially equatorial perijove to higher northern latitudes at a rate of about one degree per orbit.  One result of the precession is that Juno crosses the equator at decreasing radial distances during the inbound portion of the orbit. Recently, Juno has crossed the magnetic equator at distances of 10 Jovian radii (R<sub>J</sub>) and less.  Voyager and Galileo observations have shown the magnetic equator inside of 10 R<sub>J</sub> to be the site of numerous plasma wave phenomena including whistler-mode hiss, chorus, electron cyclotron harmonics and upper hybrid bands.  In addition, this is the location of the plasma sheet at the outer edge of the Io and Europa torii.  The Juno orbit, with its near-polar inclination carries the spacecraft through this intriguing region to higher latitudes.  This paper examines the evolution of whistler-mode chorus and hiss as well as electron cyclotron waves from the magnetic equator to higher latitudes.  While there are now statistical studies of electromagnetic waves at intermediate latitudes based on Galileo and Juno observations, this paper is designed to show details of these wave phenomena utilizing the Juno Waves instrument’s burst mode for high resolution.  Each of these wave phenomena has the potential to interact with the electrons in the inner magnetosphere and cause pitch-angle scattering and/or acceleration, so they are important in the flow of mass and energy through the Jovian system.</p>

Inhomogeneity effects on the absorption of electromagnetic high-frequency waves by magnetized Maxwellian plasmas

1990 ◽  
Vol 43 (3) ◽  
pp. 335-356 ◽  
Author(s):  
R. A. Caldela Fo ◽  
R. S. Schneider ◽  
L. F. Ziebell
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Electromagnetic Waves ◽  
Cyclotron Frequency ◽  
Electron Cyclotron ◽  
Temperature Anisotropy ◽  
Plasma Parameters ◽  
Electron Cyclotron Frequency ◽  
High Frequency Waves ◽  
The Magnetic Field

Inhomogeneity effects on the absorption of high-frequency electromagnetic waves by magnetized Maxwellian plasmas are considered, and in particular the propagation and absorption of the ordinary and extraordinary modes propagating perpendicularly to the magnetic field are analysed. We show that, for small values of the ratio of the electron plasma frequency to the electron-cyclotron frequency, the inhomogeneity effects are more important for the ordinary mode, and that for values of this ratio close to or greater than unity the effects become pronounced for the extraordinary mode. It is also shown that, for a given value of this ratio, and for a fixed value of the ratio of electron-cyclotron frequency to wave frequency, the inhomogeneity effects tend to increase as the ambient magnetic field decreases. The temperature dependence of the effect, the dependence on the direction of propagation l'elative to the inhomogeneity, the influence of temperature anisotropy, and the isolated contribution of the gradients of different plasma parameters are investigated. Several circumstances in which instabilities may occur are mentioned.

Sign in / Sign up

Export Citation Format

Share Document