Effect of Hall current and finite Larmor radius on the stability of a plasma

1980 ◽  
Vol 48 (2-3) ◽  
pp. 251-267 ◽  
Author(s):  
P. D. Ariel
Keyword(s):  
Hall Current ◽  
Larmor Radius ◽  
Finite Larmor Radius ◽  
The Stability

Effect of finite ion Larmor radius on the stability of rotating superposed fluids

1969 ◽  
Vol 47 (8) ◽  
pp. 831-834 ◽  
Author(s):  
G. L. Kalra
Keyword(s):  
Gravitational Instability ◽  
Equations Of Motion ◽  
Vortex Sheet ◽  
Larmor Radius ◽  
Simultaneous Presence ◽  
Uniform Rotation ◽  
Finite Larmor Radius ◽  
The Stability ◽  
Superposed Fluids ◽  
Macroscopic Equations

The effect of finite ion Larmor radius on the gravitational instability of two superposed fluids in uniform rotation is investigated for interchange perturbations, using the macroscopic equations of motion, where the finite ion Larmor radius effect is incorporated through off-diagonal terms in the pressure tensor. It is found that the region of stable wavelengths is enhanced due to the simultaneous presence of finite Larmor radius and a uniform rotation. A similar conclusion is also arrived at for the situation when a vortex sheet is present between the two superposed fluids.

Resistive instability in a uniformly rotating magnetoplasma

1971 ◽  
Vol 6 (1) ◽  
pp. 73-85
Author(s):  
A. D. Lunn
Keyword(s):  
Magnetic Field ◽  
Growth Rates ◽  
Larmor Radius ◽  
Closed Set ◽  
Finite Larmor Radius ◽  
Integral Methods ◽  
Stabilizing Effect ◽  
Instability Growth ◽  
Linear Differential ◽  
The Stability

A closed set of guiding centre equations, derived for a rotating plasma in a static magnetic field, is applied to the problem of the stability of a plasma in a sheared field. The rotation is found to have a stabilizing effect in the absence of resistivity.A pair of coupled, linear differential equations is derived for the rotating plasma in a weakly sheared field. Dispersion relations are obtained by phase integral methods and, in the absence of finite Larmor radius effects and rotation, instability growth rates proportional to η½13 are found which become proportional to when either is included. The inclusion of both finite Larmor radius and rotation gives growing instabilities proportional to η which are stabilized by the rotation when the finite Larmor radius terms predominate.

Evolution of nonlinear magnetosonic waves propagating obliquely to an external magnetic field in a collisionless plasma

2000 ◽  
Vol 64 (3) ◽  
pp. 211-226 ◽  
Author(s):  
DEBALINA CHAKRABORTY ◽  
K. P. DAS
Keyword(s):  
Magnetic Field ◽  
Hall Current ◽  
Collisionless Plasma ◽  
Momentum Equation ◽  
Finite Amplitude ◽  
Larmor Radius ◽  
Finite Larmor Radius ◽  
Petviashvili Equation ◽  
Flr Effects ◽  
External Uniform Magnetic Field

It is shown that the asymptotic evolution of finite-amplitude magnetosonic waves propagating obliquely to an external uniform magnetic field in a warm homogeneous plasma is governed by a Kadomtsev–Petviashvili equation having an extra dispersive term. The dispersion is provided by finite-Larmor-radius (FLR) effects in the momentum equation and by the Hall-current and electron-pressure corrections in the generalized Ohm's law. A double-layer-type solution of the equation is obtained, and the equation is shown to reduce to a KdV–Burgers equation under certain assumptions.

On the stability of the screw pinch in the CGL model

1976 ◽  
Vol 16 (3) ◽  
pp. 261-283 ◽  
Author(s):  
Krishna M. Srivastava ◽  
F. Waelbroeck
Keyword(s):  
Magnetic Field ◽  
Wave Number ◽  
Larmor Radius ◽  
Anisotropic Pressure ◽  
Finite Larmor Radius ◽  
Main Column ◽  
First Order Correction ◽  
The Stability ◽  
The Magnetic Field ◽  
Ideal Plasma

We have investigated the stability of the screw pinch with the help of the double adiabatic (CGL) equations including the finite Larmor radius effects through the anisotropic pressure tensor. The calculations are approximate, with FLR treated as a first-order correction to the ideal plasma equations. The dispersion relation has been solved for various values of R2 = p∥/p⊥ and α for the rale and imaginary part of the frequency (ω = ωR ± iωI) in three particular cases: (a) μ = 0, the θ-pinch, (b) μ = ∞, the Z-pinch, (c) μ = -α/m, field distubances parallel to the equilibrium field. Here μ is the pitch of the magnetic field in the pressureless plasma surrounding the main column, α is the wave number, m is the azimuthal number, p∥ and p⊥ are plasma pressures along and perpendicular to the magnetic field.

Boundary conditions in the presence of Hall current of finite ion Larmor radius effects

1972 ◽  
Vol 7 (3) ◽  
pp. 545-551 ◽  
Author(s):  
R. J. Hosking ◽  
G. L. Kalra
Keyword(s):  
Boundary Conditions ◽  
Hall Current ◽  
Larmor Radius ◽  
The Stability

Boundary conditions appropriate to a model with finite ion mass corrections of ideal hydromagnetic theory are reviewed. It is shown that these boundary conditions have been correctly satisfied in earlier theory for the stability of an interface between two semi-infinite regions. This theory predicts instability due to Hall current.

scholarly journals Linear Vlasov theory of a magnetised, thermally stratified atmosphere

2016 ◽  
Vol 82 (5) ◽  
Author(s):  
Rui Xu ◽  
Matthew W. Kunz
Keyword(s):  
Growth Rate ◽  
Temperature Gradient ◽  
Physical Interpretation ◽  
Magnetic Confinement ◽  
Larmor Radius ◽  
Drift Waves ◽  
Finite Larmor Radius ◽  
Electron Temperature Gradient ◽  
Confinement Fusion ◽  
The Stability

The stability of a collisionless, magnetised plasma to local convective disturbances is examined, with a focus on kinetic and finite-Larmor-radius effects. Specific application is made to the outskirts of galaxy clusters, which contain hot and tenuous plasma whose temperature increases in the direction of gravity. At long wavelengths (the ‘drift-kinetic’ limit), we obtain the kinetic version of the magnetothermal instability (MTI) and its Alfvénic counterpart (Alfvénic MTI), which were previously discovered and analysed using a magnetofluid (i.e. Braginskii) description. At sub-ion-Larmor scales, we discover an overstability driven by the electron-temperature gradient of kinetic-Alfvén drift waves – the electron MTI (eMTI) – whose growth rate is even larger than the standard MTI. At intermediate scales, we find that ion finite-Larmor-radius effects tend to stabilise the plasma. We discuss the physical interpretation of these instabilities in detail, and compare them both with previous work on magnetised convection in a collisional plasma and with temperature-gradient-driven drift-wave instabilities well known to the magnetic-confinement-fusion community. The implications of having both fluid and kinetic scales simultaneously driven unstable by the same temperature gradient are briefly discussed.

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