Comment on “Instability of the Shukla mode in a dusty plasma containing equilibrium density and magnetic field inhomogeneities” [Phys. Plasmas11, 1732 (2004)] and “New resonance and cut-off for low-frequency electromagnetic waves in dusty magnetoplasmas” [Phys. Plasmas11, 2307 (2004)]

2004 ◽  
Vol 11 (8) ◽  
pp. 4154-4155 ◽  
Author(s):  
Leonid Rudakov
Keyword(s):  
Magnetic Field ◽  
Dusty Plasma ◽  
Electromagnetic Waves ◽  
Low Frequency ◽  
Equilibrium Density

Instability of the Shukla mode in a dusty plasma containing equilibrium density and magnetic field inhomogeneities

2004 ◽  
Vol 11 (4) ◽  
pp. 1732-1734 ◽  
Author(s):  
P. K. Shukla ◽  
R. Bharuthram ◽  
R. Schlickeiser
Keyword(s):  
Magnetic Field ◽  
Dusty Plasma ◽  
Equilibrium Density

Purely growing electromagnetic modes in high-β plasmas

1974 ◽  
Vol 11 (3) ◽  
pp. 461-470 ◽  
Author(s):  
G. S. Lakhina ◽  
B. Buti ◽  
Girija Nayar
Keyword(s):  
Magnetic Field ◽  
Growth Rates ◽  
Electromagnetic Waves ◽  
Low Frequency ◽  
Frequency Instability ◽  
Wave Number ◽  
Unstable Wave ◽  
Distribution Index ◽  
Kinetic Pressure ◽  
Low Frequency Instability

Electromagnetic waves propagating transverse to an external magnetic field in a high-β (β being the ratio of the kinetic pressure to the magnetic pressure) plasma become unstable through purely growing modes when β∥e, (electron β parallel to the magnetic field) exceeds a certain minimum value β∥*. For J ≦ 2 (J being the distribution index), the region of instability consists of a single band of unstable wavenumbers k, whereas for J ≥ 3 more than one unstable wave number band may exist. The growth rates are largest for J = 0, and tend to decrease as J increases. The presence of hot ions increases the instability region by exciting a low-frequency instability. This instability gets excited at considerably lowered values of β‖e, and has growth rates of the order of ion cyclotron frequency. The effect of T‖i/T‖e and T‖e/T⊥e is destabilizing, whereas that of T⊥i/T⊥e is stabilizing.

WAVES IN A RAREFIED IONIZED GAS PROPAGATED TRANSVERSE TO AN EXTERNAL MAGNETIC FIELD

1961 ◽  
Vol 39 (7) ◽  
pp. 1044-1057 ◽  
Author(s):  
Tomiya Watanabe
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Electromagnetic Waves ◽  
Low Frequency ◽  
Sound Waves ◽  
Ionized Gas ◽  
Frequency Limit ◽  
Electrons And Ions ◽  
Hydromagnetic Waves ◽  
Perturbed Magnetic Field

Waves being propagated in a rarefied and fully ionized gas and transverse to an external magnetic field have been studied, particularly hydromagnetic waves. Three modes of waves, in which the perturbed magnetic field is parallel to the external magnetic field, are found to be propagated. In a high-frequency limit, they tend to electromagnetic waves, electron sound waves, and ion sound waves. In the condition that the Alfvén velocity is greater than the ion sound velocity but smaller than the light velocity, the last mode tends to a hydromagnetic wave in the low-frequency limit. The other two modes of waves can be propagated only at frequencies higher than the critical frequencies, both of which almost equal the electron plasma frequency. The condition that hydromagnetic waves should be attenuated severely due to collisions between electrons and ions has been derived.

scholarly journals Collisional and resonance absorption of electromagnetic waves in a weakly collisional, inhomogeneous magnetoplasma slab

2020 ◽  
Vol 9 (2) ◽  
pp. 25-30
Author(s):  
F. Rawwagah ◽  
M. Al-Ali ◽  
A. Al-Khateeb ◽  
M. Bawa'aneh
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Waves ◽  
Electron Cyclotron Resonance ◽  
Cyclotron Frequency ◽  
Low Frequency ◽  
Electron Cyclotron ◽  
The Body ◽  
Absorption Bands ◽  
Dc Magnetic Field ◽  
Frequency Branch

Absorbance of normally incident electromagnetic wave on a cold, weakly collisional, and inhomogeneous magnetoplasma slab is investigated. The plasma density is Budden-like sinusoidal profile, where the inhomogeniety is treated as a multilayered system of homogeneous sub-cells within the transfer matrix technique. For incident wave frequencies much above the ion cyclotron frequency, only right hand circularly polarized waves are relevant for wave propagation parallel to a static magnetic field. Calculations are performed in normalized parameters, that make the results suitable for many applications including atmospheric and laboratory plasmas. The presence of the dc-magnetic field leads to the formation of two absorption bands explained by plasma collisional dissipation and electron cyclotron resonance in the low frequency branch of the $R$-wave below the electron cyclotron frequency. The transmittance shows the emergence of the low frequency electron cyclotron wave, which becomes a Whistler mode at very low frequency. More detailed discussion on the effect of plasma collisionality, inhomogeneity, and dc-magnetic field on the propagation characteristics is given at the relevant place within the body of the manuscript.

Tripolar vortices in ion-temperature-gradient mode with non-Maxwellian electrons in an inhomogeneous magnetoplasma

2017 ◽  
Vol 95 (7) ◽  
pp. 650-654
Author(s):  
Anisa Qamar ◽  
Javed Iqbal ◽  
U. Zakir ◽  
Arshad M. Mirza
Keyword(s):  
Magnetic Field ◽  
Temperature Gradient ◽  
Low Frequency ◽  
Equilibrium Density ◽  
Ion Temperature ◽  
Ion Temperature Gradient ◽  
Field Gradients ◽  
Frequency Plasma ◽  
Magnetic Field Gradients ◽  
Kappa Distributed Electrons

We consider a low frequency plasma comprising of Kappa distributed electrons and Maxwellian ions embedded in an external magnetic field in toroidal ion-temperature-gradient driven modes. A set of nonlinear equations are derived in the presence of equilibrium density, temperature, and magnetic field gradients. In the nonlinear regime, solutions in the form of tripolar vortices are derived by using Braginskii’s transport equations. It has been observed that the scale lengths over which the nonlinear vortex structures form get modified in the presence of Kappa distributed electrons. In tokamak the present study is applicable where non-Maxwellian population has been observed in electron cyclotron heating experiments and resonant frequency heating.

Low frequency dusty plasma modes in a uniform magnetic field

2002 ◽  
Vol 9 (10) ◽  
pp. 4396-4398 ◽  
Author(s):  
Xiaogang Wang ◽  
Zheng-Xiong Wang ◽  
Chun-Hua Wang ◽  
Bin Guo
Keyword(s):  
Magnetic Field ◽  
Dusty Plasma ◽  
Uniform Magnetic Field ◽  
Low Frequency
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