Low-frequency drift-induced instabilities in a magnetized two-ion plasma

1986 ◽  
Vol 35 (3) ◽  
pp. 393-412 ◽  
Author(s):  
R. Bharuthram ◽  
M. A. Hellberg
Keyword(s):  
Dispersion Relation ◽  
Numerical Solutions ◽  
Cyclotron Frequency ◽  
Low Frequency ◽  
Frequency Drift ◽  
Transition Diagram ◽  
Electrostatic Waves ◽  
Ion Plasma ◽  
Parameter Values ◽  
A Current

Numerical solutions of a dispersion relation for low-frequency electrostatic waves in a current-carrying, cold, weakly collisional, magnetized two-ion plasma are used to discuss the two-stream and resistive natures of the ion-ion hybrid instability. An instability with analogous behaviour is found to be associated with the light ion cyclotron frequency. Analytical results explain the behaviour. A numerically derived transition diagram summarizes the parameter values for which transitions between different modes take place.

A numerical investigation of current-driven instabilities near the ion-ion hybrid frequency

1984 ◽  
Vol 32 (3) ◽  
pp. 387-398 ◽  
Author(s):  
Diane J. Grayson ◽  
M. A. Hellberg
Keyword(s):  
Dispersion Relation ◽  
Numerical Investigation ◽  
Electrostatic Waves ◽  
Ion Plasma ◽  
Hybrid Frequency ◽  
Parameter Values ◽  
A Current

A dispersion relation for electrostatic waves in a current-carrying, resistive, magnetized, two-ion plasma has been solved numerically for a range of parameter values. The behaviour of the resistive ion-ion hybrid instability is described and in addition a two-stream ion-ion hybrid instability is identified.

Ion-cyclotron modes in weakly relativistic plasmas

1994 ◽  
Vol 51 (3) ◽  
pp. 371-379 ◽  
Author(s):  
Chandu Venugopal ◽  
P. J. Kurian ◽  
G. Renuka
Keyword(s):  
Dispersion Relation ◽  
High Frequency ◽  
Low Frequency ◽  
Dispersion Relations ◽  
The Other ◽  
Larmor Radius ◽  
Relativistic Plasmas ◽  
Ion Plasma ◽  
Maxwellian Plasma ◽  
Relativistic Dispersion

We derive a dispersion relation for the perpendicular propagation of ioncyclotron waves around the ion gyrofrequency ω+ in a weaklu relaticistic anisotropic Maxwellian plasma. These waves, with wavelength greater than the ion Larmor radius rL+ (k⊥ rL+ < 1), propagate in a plasma characterized by large ion plasma frequencies (). Using an ordering parameter ε, we separated out two dispersion relations, one of which is independent of the relativistic terms, while the other depends sensitively on them. The solutions of the former dispersion relation yield two modes: a low-frequency (LF) mode with a frequency ω < ω+ and a high-frequency (HF) mode with ω > ω+. The plasma is stable to the propagation of these modes. The latter dispersion relation yields a new LF mode in addition to the modes supported by the non-relativistic dispersion relation. The two LF modes can coalesce to make the plasma unstable. These results are also verified numerically using a standard root solver.

Finite-frequency surface waves on current sheets

1991 ◽  
Vol 45 (3) ◽  
pp. 389-406 ◽  
Author(s):  
K. P. Wessen ◽  
N. F. Cramer
Keyword(s):  
Magnetic Field ◽  
Dispersion Relation ◽  
Surface Waves ◽  
Cyclotron Frequency ◽  
Low Frequency ◽  
Dielectric Tensor ◽  
Magnetic Field Direction ◽  
Field Reversal ◽  
Ion Cyclotron ◽  
The Magnetic Field

The dispersion relation for low-frequency surface waves at a current sheet between two magnetized plasmas is derived using the cold-plasma dielectric tensor with finite ion-cyclotron frequency. The magnetic field direction is allowed to change discontinuously across the sheet, but the plasma density remains constant. The cyclotron frequency causes a splitting of the dispersion relation into a number of mode branches with frequencies both less than and greater than the ion-cyclotron frequency. The existence of these modes depends in particular upon the degree of magnetic field discontinuity and the direction of wave propagation in the sheet relative to the magnetic field directions. Sometimes two modes can exist for the same direction of propagation. The existence of modes undamped by Alfvén resonance absorption is predicted. Analytical solutions are obtained in the low-frequency and magnetic-field-reversal limits. The solutions are obtained numerically in the general case.

Stability of anisotropic plasmas to almost-perpendicular magnetosonic waves

1971 ◽  
Vol 6 (3) ◽  
pp. 495-512 ◽  
Author(s):  
R. W. Landau† ◽  
S. Cuperman
Keyword(s):  
Magnetic Field ◽  
Dispersion Relation ◽  
Simple Form ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Alfven Wave ◽  
Larmor Radius ◽  
Ion Plasma ◽  
The Stability ◽  
The Magnetic Field

The stability of anisotropic plasmas to the magnetosonic (or right-hand compressional Alfvén) wave, near the ion cyclotron frequency, propagating almost perpendicular to the magnetic field, is investigated. For this case, and for wavelengths larger than the ion Larmor radius and for large ion plasma frequency (w2p+ ≫ Ωp+) the dispersion relation is obtained in a simple form. It is shown that for T # T' (even T ≫ T) no instabifity occurs. The resonant ters are also included, and it is shown that there is no resonant instabifity, only damping.

Electrostatic waves in the shock ramp and their effect on plasma energetics.

2021 ◽  
Author(s):  
Ahmad Lalti ◽  
Yuri Khotyaintsev ◽  
Daniel Graham ◽  
Andris Vaivad ◽  
Andreas Johlander
Keyword(s):  
Solar Wind ◽  
Acoustic Waves ◽  
Cyclotron Frequency ◽  
Particle Interactions ◽  
Ion Acoustic Waves ◽  
Electrostatic Waves ◽  
Ion Plasma ◽  
Magnetospheric Multiscale ◽  
Bernstein Waves ◽  
Open Question

&lt;p&gt;Energy dissipation at collisionless shocks is still an open question. Wave particle interactions are believed to be at the heart of it, but the exact details are still to be figured out. One type of waves that is known to be an efficient dissipator of solar wind kinetic energy are electrostatic waves in the shock ramp, such as ion acoustic waves with frequency around the ion plasma frequency or Bernstein waves with frequency around the electron cyclotron frequency and its harmonics. The electric field of such waves is typically larger than 100 mV/m, large enough to disturb particle dynamics. In this study we use the magnetospheric multiscale (MMS) spacecraft, to investigate the source and evolution of electrostatic waves in the shock ramp of quasi-perpendicular super-critical shocks, and study their effect on solar wind thermalization.&lt;/p&gt;

Stability of relativistic anisotropic plasmas to perpendicular magnetosonic waves

1970 ◽  
Vol 4 (3) ◽  
pp. 495-510 ◽  
Author(s):  
R. W. Landau ◽  
S. Cuperman
Keyword(s):  
Dispersion Relation ◽  
Cyclotron Frequency ◽  
Plasma Frequency ◽  
Interplanetary Medium ◽  
Alfven Wave ◽  
Larmor Radius ◽  
First Order ◽  
Ion Plasma ◽  
The Stability ◽  
The Magnetic Field

The stability of relativistic anisotropic plasmas to the magnetosonic (or righthand compressional Alfvén) wave, near the ion cyclotron frequency, propagating perpendicular to the magnetic field, is investigated. For this case, and for wavelengths larger than the ion Larmor radius and large ion plasma frequency () the dispersion relation is obtained in a simple form and solved. It is shown that for T‖ ╪ T⊥ (even T‖ ≥ T⊥) no instability occurs. This conclusion applies also to the case of the anisotropic interplanetary medium.We note a peculiarity of the dispersion relation. Zero-order and first-order terms cancel so that the relation is of second order in our expansion parameter. The non-relativistic numerical results of Fredricks and Kennel are recovered.

Low-frequency electrostatic waves in a magnetized, current-free, heavy negative ion plasma

2013 ◽  
Vol 79 (6) ◽  
pp. 1107-1111 ◽  
Author(s):  
S. H. KIM ◽  
R. L. MERLINO ◽  
J. K. MEYER ◽  
M. ROSENBERG
Keyword(s):  
Large Fraction ◽  
Low Frequency ◽  
Negative Ions ◽  
Wave Mode ◽  
Negative Ion ◽  
Electrostatic Wave ◽  
Electrostatic Waves ◽  
Positive Ions ◽  
Ion Plasma ◽  
The Waves

AbstractWe report experimental observations of a low-frequency (≪ ion gyrofrequency) electrostatic wave mode in a magnetized cylindrical (Q machine) plasma containing positive ions, very few electrons and a relatively large fraction (n−/ne > 103) of heavy negative ions (m−/m+ ≈ 10), and no magnetic field-aligned current. The waves propagate nearly perpendicular to B with a multiharmonic spectrum. The maximum wave amplitude coincided spatially with the region of largest density gradient suggesting that the waves were excited by a drift instability in a nearly electron-free positive ion–negative ion plasma

Non-symmetric two-stream instability

1977 ◽  
Vol 17 (1) ◽  
pp. 23-39 ◽  
Author(s):  
S. Cuperman ◽  
L. Gomberoff ◽  
I. Roth ◽  
W. Bernstein
Keyword(s):  
Numerical Solutions ◽  
Cyclotron Frequency ◽  
Particle Density ◽  
Maximum Growth ◽  
Systematic Investigation ◽  
Marginal Stability ◽  
Theoretical Problem ◽  
Electrostatic Waves ◽  
Dirac Delta ◽  
Stream Instability

The recent Plum Brook—NASA experiments on counterstreaming plasma instabilities in which electric field emissions at frequencies [(n + ½) ±α]ωe (n = 1, 2, 3,…, 9, α < 0·5) have been observed, raised the theoretical problem of the non-symmetric two-stream instability. This is the case in which the counterstreaming beams have different velocities in the directions parallel and perpendicular to the static magnetic fields as well as different particle density.We investigate theoretically this problem. The instability of quasi-electrostatic waves at shifted half odd integer multiples of the cyclotron frequency, due to two non-symmetric counterstreaming electron beams, is considered. The beam velocities parallel and perpendicular to the static magnetic field are represented by different double Dirac delta functions; no parameter limitation is imposed. A systematic investigation of (i) the coupling between plasma modes and cyclotron modes and (ii) the coupling between cyclotron modes (beam 1) and cyclotron modes (beam 2) resulting in shifted half odd integer multiples of the cyclotron frequency is carried out.The results include approximate but simple analytical expressions for maximum growth rates and for marginal stability as well as exact numerical solutions for the detailed unstable spectra (1 ≤ m ≤ 20) in both ωτ- and kr-space. The relative weakening or suppression of certain modes is also predicted.

Coupling of the Okuda–Dawson model with a shear current-driven wave and the associated instability

2013 ◽  
Vol 79 (6) ◽  
pp. 1129-1131
Author(s):  
W. MASOOD ◽  
H. SALEEM
Keyword(s):  
Plasma Flow ◽  
Low Frequency ◽  
Dust Particles ◽  
Density Inhomogeneity ◽  
Electrostatic Waves ◽  
Ion Plasma ◽  
Shear Current ◽  
Stationary Dust

AbstractIt is pointed out that the Okuda–Dawson mode can couple with the newly proposed current-driven wave. It is also shown that the Shukla–Varma mode can couple with these waves if the density inhomogeneity is taken into account in a plasma containing stationary dust particles. A comparison of several low-frequency electrostatic waves and instabilities driven by shear current and shear plasma flow in an electron–ion plasma with and without stationary dust is also presented.

scholarly journals Dispersion relation of low-frequency electrostatic waves in plasmas with relativistic electrons

2016 ◽  
Vol 34 (1) ◽  
pp. 178-186 ◽  
Author(s):  
B. Touil ◽  
A. Bendib ◽  
K. Bendib-Kalache ◽  
C. Deutsch
Keyword(s):  
Dispersion Relation ◽  
Debye Length ◽  
Low Frequency ◽  
Relativistic Effects ◽  
Relativistic Electrons ◽  
Complex Frequency ◽  
Ion Temperature ◽  
Electrostatic Waves ◽  
Relativistic Regime ◽  
Analytic Expressions

AbstractThe dispersion relation of electrostatic waves with phase velocities smaller than the electron thermal velocity is investigated in relativistic temperature plasmas. The model equations are the electron relativistic collisionless hydrodynamic equations and the ion non-relativistic Vlasov equation, coupled to the Poisson equation. The complex frequency of electrostatic modes are calculated numerically as a function of the relevant parameters kλDe and ZTe/Ti where k is the wavenumber, λDe, the electron Debye length, Te and Ti the electron and ion temperature, and Z, the ion charge number. Useful analytic expressions of the real and imaginary parts of frequency are also proposed. The non-relativistic results established in the literature from the kinetic theory are recovered and the role of the relativistic effects on the dispersion and the damping rate of electrostatic modes is discussed. In particular, it is shown that in highly relativistic regime the electrostatic waves are strongly damped.

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