Finite Larmor radius and Hall effects on thermosolutal instability of a plasma

1990 ◽  
Vol 168 (2) ◽  
pp. 331-339
Author(s):  
K. C. Sharma ◽  
Urvashi Gupta ◽  
D. V. S. Pathania
Keyword(s):  
Larmor Radius ◽  
Finite Larmor Radius ◽  
Hall Effects

scholarly journals Finite Larmor Radius and Hall Effects on Thermal Instability of a Plasma in Porous Medium

1994 ◽  
Vol 49 (4-5) ◽  
pp. 547-551 ◽  
Author(s):  
R. C. Sharma ◽  
V. K. Bhardwaj
Keyword(s):  
Porous Medium ◽  
Thermal Instability ◽  
Wave Number ◽  
Larmor Radius ◽  
Stationary Convection ◽  
Number Range ◽  
Finite Larmor Radius ◽  
Hall Effects ◽  
Wave Number Range ◽  
Medium Permeability

Abstract The thermal instability of a plasma in a porous medium in the presence of a finite Larmor radius (FLR) and Hall effects is considered. Oscillatory m odes due to the presence of a magnetic field (and hence the presence of FLR and Hall effects) are introduced. For stationary convection, the FLR may have a stabilizing or destabilizing effect, but a completely stabilizing one for a certain wave-number range. Similarly, the Hall currents may have a stabilizing or destabilizing effect but a completely stabilizing one for the same wave-number range under certain condition, whereas the medium permeability always has a destabilizing effect for stationary convection.

Excitation of Alfvén waves by fast particles in a finite pressure plasma of adiabatic traps

1978 ◽  
Vol 20 (1) ◽  
pp. 137-148 ◽  
Author(s):  
B. I. Meerson ◽  
A. B. Mikhallovskii ◽  
O. A. Pokhotelov
Keyword(s):  
Uniform Magnetic Field ◽  
Alfven Waves ◽  
Larmor Radius ◽  
Alfvén Waves ◽  
Trapped Particles ◽  
Resonance Effects ◽  
Finite Larmor Radius ◽  
Pressure Plasma ◽  
Pressure Stabilization ◽  
Instability Growth

Resonant excitation of Alfvén waves by fast particles in a finite pressure plasma in a non-uniform magnetic field is studied. Plasma compressibility in the wave field is determined both by the curvature of the magnetic lines of force and finite Larmor radius of fast particles. A general expression for the instability growth rate is obtained and analyzed; the applicability of the results obtained in the previous paper has also been studied. The finite pressure stabilization of the trapped particles instability has been found. The bounce-resonance effects are analyzed.

scholarly journals Diffusion at the Earth magnetopause: enhancement by Kelvin-Helmholtz instability

2007 ◽  
Vol 25 (1) ◽  
pp. 271-282 ◽  
Author(s):  
R. Smets ◽  
G. Belmont ◽  
D. Delcourt ◽  
L. Rezeau
Keyword(s):  
Magnetic Field ◽  
Distribution Functions ◽  
Larmor Radius ◽  
Simple Analytical Model ◽  
Helmholtz Instability ◽  
Field Reversal ◽  
Finite Larmor Radius ◽  
The Earth ◽  
Specific Distribution ◽  
The Magnetic Field

Abstract. Using hybrid simulations, we examine how particles can diffuse across the Earth's magnetopause because of finite Larmor radius effects. We focus on tangential discontinuities and consider a reversal of the magnetic field that closely models the magnetopause under southward interplanetary magnetic field. When the Larmor radius is on the order of the field reversal thickness, we show that particles can cross the discontinuity. We also show that with a realistic initial shear flow, a Kelvin-Helmholtz instability develops that increases the efficiency of the crossing process. We investigate the distribution functions of the transmitted ions and demonstrate that they are structured according to a D-shape. It accordingly appears that magnetic reconnection at the magnetopause is not the only process that leads to such specific distribution functions. A simple analytical model that describes the built-up of these functions is proposed.

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