scholarly journals Dispersion curves for the generalized Bernstein modes

1973 ◽  
Vol 9 (1) ◽  
pp. 89-100 ◽  
Author(s):  
S. Puri ◽  
F. Leuterer ◽  
M. Tutter
Keyword(s):  
Magnetic Field ◽  
Exact Solution ◽  
Cold Plasma ◽  
Dispersion Curves ◽  
Harmonic Waves ◽  
Plasma Model ◽  
Maxwellian Plasma ◽  
Cyclotron Harmonics ◽  
Shrinking Regions ◽  
Cyclotron Harmonic

Dispersion curves are plotted for the extraordinary branch of the electron- and ion-cyclotron harmonic waves propagating perpendicularly to the static magnetic field in a non-relativistic, hot Maxwellian plasma, without invoking the electrostatic approximation. It is found that, except in the vicinity of the cyclotron harmonics and the hybrid resonances, either the cold-plasma or the electrostatic approximation are accurate representations of the exact solution. The hybrid resonances of the cold-plasma model become monotonically shrinking regions of low group velocity as the temperature is increased, till all discernible evidence of these resonances disappears as the parameters corresponding to the thermonuclear plasmas are approached.

FREQUENCY VARIATION IN IONOSPHERIC CYCLOTRON HARMONIC SERIES OBTAINED BY THE ALOUETTE I SATELLITE

1966 ◽  
Vol 44 (5) ◽  
pp. 987-994 ◽  
Author(s):  
R. E. Barrington ◽  
Luise Herzberg
Keyword(s):  
Magnetic Field ◽  
Cyclotron Frequency ◽  
Harmonic Series ◽  
Frequency Variation ◽  
Theoretical Studies ◽  
Experimental Accuracy ◽  
Laboratory Results ◽  
Cyclotron Harmonics ◽  
Cyclotron Harmonic ◽  
Recent Laboratory

Ionograms produced by the Alouette I topside sounder frequently show well-developed series of cyclotron harmonics. Their frequencies have been determined from A (amplitude) scans with an accuracy of ~0.02 Mc/s for the sweep range of 1 to 6 Mc/s. In all cases examined, the frequencies of all of the members of the harmonic series are, within the experimental accuracy, integral multiples of the cyclotron frequency derived from the best present estimates of the earth's magnetic field strength at the satellite height. This result is discussed in the light of recent laboratory results and theoretical studies.

scholarly journals Polarization properties of Gendrin mode waves observed in the Earth's magnetosphere: observations and theory

2009 ◽  
Vol 27 (12) ◽  
pp. 4429-4433 ◽  
Author(s):  
O. P. Verkhoglyadova ◽  
B. T. Tsurutani
Keyword(s):  
Magnetic Field ◽  
Wave Propagation ◽  
Electromagnetic Wave ◽  
Excellent Agreement ◽  
Cold Plasma ◽  
Outer Zone ◽  
Plasma Model ◽  
Circularly Polarized ◽  
Ambient Magnetic Field ◽  
Measured Angle

Abstract. We show a case of an outer zone magnetospheric electromagnetic wave propagating at the Gendrin angle, within uncertainty of the measurements. The chorus event occurred in a "minimum B pocket". For the illustrated example, the measured angle of wave propagation relative to the ambient magnetic field θkB was 58°±4°. For this event the theoretical Gendrin angle was 62°. Cold plasma model is used to demonstrate that Gendrin mode waves are right-hand circularly polarized, in excellent agreement with the observations.

scholarly journals Higher Frequency Spectrum of a Diffuse Linear Pinch with Multiple Ion Species

1985 ◽  
Vol 38 (2) ◽  
pp. 143 ◽  
Author(s):  
WN-C Sy
Keyword(s):  
Magnetic Field ◽  
Cold Plasma ◽  
Cyclotron Frequency ◽  
Cutoff Frequency ◽  
Plasma Model ◽  
Frequency Effects ◽  
Soluble Model ◽  
Ion Cyclotron ◽  
Arbitrary Magnetic Field ◽  
Ion Species

A cold plasma model which takes into account finite ion cyclotron frequency effects and multiple ion species has been developed for wave propagation in arbitrary magnetic field geometries. This model has been used to derive an elegant system of normal mode equations for a 10w-fJ diffuse linear pinch. From a soluble model, general features of the spectrum are discussed up to and including the ion cyclotron range of frequencies. It is indicated that in the vicinity of the ion-ion hybrid cutoff frequency, there could exist global eigenmodes which might be useful for supplementary heating of diffuse linear pinches.

scholarly journals Two typical collective behaviors of the heavy ions expanding in cold plasma with ambient magnetic field

2021 ◽  
Vol 33 (7) ◽  
pp. 076602
Author(s):  
Guo-Liang Peng ◽  
Jun-Jie Zhang ◽  
Jian-Nan Chen ◽  
Tai-Jiao Du ◽  
Hai-Yan Xie
Keyword(s):  
Magnetic Field ◽  
Heavy Ions ◽  
Cold Plasma ◽  
Collective Behaviors ◽  
Ambient Magnetic Field

On the existence of compressional MHD oscillations in an inhomogeneous magnetoplasma

1990 ◽  
Vol 44 (2) ◽  
pp. 361-375 ◽  
Author(s):  
Andrew N. Wright
Keyword(s):  
Magnetic Field ◽  
Wave Equation ◽  
Density Distribution ◽  
Cold Plasma ◽  
Wave Equations ◽  
Perturbation Field ◽  
Plasma Density Distribution ◽  
Background Magnetic Field ◽  
Transverse Fields ◽  
The Magnetic Field

In a cold plasma the wave equation for solely compressional magnetic field perturbations appears to decouple in any surface orthogonal to the background magnetic field. However, the compressional fields in any two of these surfaces are related to each other by the condition that the perturbation field b be divergence-free. Hence the wave equations in these surfaces are not truly decoupled from one another. If the two solutions happen to be ‘matched’ (i.e. V.b = 0) then the medium may execute a solely compressional oscillation. If the two solutions are unmatched then transverse fields must evolve. We consider two classes of compressional solutions and derive a set of criteria for when the medium will be able to support pure compressional field oscillations. These criteria relate to the geometry of the magnetic field and the plasma density distribution. We present the conditions in such a manner that it is easy to see if a given magnetoplasma is able to executive either of the compressional solutions we investigate.

Torsional oscillations of a fluid sphere with a rigid boundary in a uniform magnetic field

1966 ◽  
Vol 24 (2) ◽  
pp. 275-284
Author(s):  
R. A. Wentzell
Keyword(s):  
Magnetic Field ◽  
Exact Solution ◽  
Uniform Magnetic Field ◽  
Perfect Conductor ◽  
Rigid Boundary ◽  
Torsional Oscillations ◽  
Magnetic Viscosity ◽  
Eigen Values ◽  
Infinite Conductivity ◽  
Axis Of Symmetry

Plumpton & Ferraro (1955) considered the torsional oscillations of an infinitely conducting sphere in a uniform magnetic field. They showed that if the fluid and magnetic viscosity were assumed to be zero in the governing differential equations, then a continuous spectrum of eigenvalues could be obtained. This novel feature was clarified by Stewartson (1957) when he obtained the exact solution and showed that in the correct limit of a perfect conductor the eigen-values are discrete. Furthermore, in the limit of infinite conductivity the oscillations occur only on the axis of symmetry (figure 1).

Cerenkov and cyclotron instabilities in a plasma stream

1967 ◽  
Vol 1 (1) ◽  
pp. 1-27 ◽  
Author(s):  
C. F. Knox
Keyword(s):  
Magnetic Field ◽  
Plane Wave ◽  
Cold Plasma ◽  
Numerical Calculations ◽  
Graphical Form ◽  
Plasma Stream ◽  
Wave Growth ◽  
Stationary Medium ◽  
Phase Propagation ◽  
Positive Ion

The model of a stationary medium traversed by a weak plasma stream directed along a magnetic field is investigated. The usual linear treatment is adopted, and the stream is taken to be ‘cold’, with only electron (perturbation) motions considered. The objective is to assess the plane-wave growth associated with both Cerenkov and cyclotron instabilities; in particular, the dependence of the growth on frequency and angle of phase propagation. The main discussion is of the case when the stationary medium is a cold plasma in which both electron and positive ion motions are taken into account. Various expressions for the growth are derived, and numerical calculations are presented in graphical form.

scholarly journals Excitation of electron cyclotron harmonic waves in the inner Saturn magnetosphere within local plasma injections

2010 ◽  
Vol 115 (A12) ◽  
pp. n/a-n/a ◽  
Author(s):  
X. Tao ◽  
R. M. Thorne ◽  
R. B. Horne ◽  
S. Grimald ◽  
C. S. Arridge ◽  
...  
Keyword(s):  
Electron Cyclotron ◽  
Harmonic Waves ◽  
Cyclotron Harmonic
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