Relaxation of a temperature anisotropy in a collisionless plasma

1970 ◽  
Vol 4 (1) ◽  
pp. 21-41 ◽  
Author(s):  
C. Montes ◽  
J. Coste ◽  
G. Diener
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Relaxation Process ◽  
Time Scales ◽  
Collisionless Plasma ◽  
Electron Plasma ◽  
Temperature Anisotropy ◽  
Quasilinear Theory ◽  
Aperiodic Instability

We study the quasifinear relaxation of an aperiodic instability, namely the instability caused by the temperature anisotropy of a collisionless electron plasma in the absence of an external magnetic field. We give a detailed description of the relaxation process and we examine the validity of the quasilinear theory (existence of separate time scales, quasilinearity of the particles' orbits).

scholarly journals Weibel instability in a plasma with nonzero external magnetic field

2012 ◽  
Vol 30 (7) ◽  
pp. 1051-1054 ◽  
Author(s):  
O. A. Pokhotelov ◽  
M. A. Balikhin
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Dispersion Relation ◽  
External Magnetic Field ◽  
Linear Growth ◽  
Cyclotron Frequency ◽  
Linear Growth Rate ◽  
Temperature Anisotropy ◽  
Formal Similarity ◽  
Weibel Instability

Abstract. The theory of the Weibel instability is generalized for the case of a plasma immersed in a nonzero external magnetic field. It is shown that the presence of this external field modifies the dispersion relation for this mode which now possesses a nonzero frequency. The explicit expression for the real and imaginary parts of the frequency is then calculated. It turns out that the linear growth rate remains unchanged, whereas the frequency becomes nonzero due to the finite value of the electron cyclotron frequency. The frequency of the Weibel mode is found to be proportional to the electron temperature anisotropy. The formal similarity of the Weibel and drift-mirror instabilities is outlined.

scholarly journals Stokes Parameters for Thomson Scattering in Magnetized Plasma

1990 ◽  
Vol 142 ◽  
pp. 93-94
Author(s):  
Chih-Kang Chou ◽  
Hui-Hwa Chen
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Electric Field ◽  
Collisionless Plasma ◽  
Thomson Scattering ◽  
Density Fluctuations ◽  
Magnetized Plasma ◽  
Stokes Parameters ◽  
Retarded Time ◽  
Image Position

The effect of a superstrong magnetic field on neutron stars or white dwarfs is studied for Thomson scattering in a fully ionized collisionless. plasma. The equation of motion for an electron in the presence of both the induced electric field of the plasma and a static uniform external magnetic field is used to determine the acceleration of the electron. The collective plasma effects due to the field and density fluctuations are investigated by using the test-particle picture. The scattering of a photon by a plasma is a function of the acceleration of particles by the electric field of the incident wave and the static external magnetic field Assuming that the electrons are distributed with density the radiation field far from the scattering center is where the delta function indicates that all quantities are to be evaluated at the retarded time and δλ is the angle between the wave vector and the Poynting vector, which is given by

scholarly journals 2D ELECTRON IN AN EXTERNAL MAGNETIC FIELD IN THE PRESENCE OF DISSIPATION

1995 ◽  
Vol 09 (06) ◽  
pp. 707-718 ◽  
Author(s):  
G. CRISTOFANO ◽  
D. GIULIANO ◽  
G. MAIELLA ◽  
L. VALENTE
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Coherent State ◽  
Transport Properties ◽  
Time Scales ◽  
Ground State ◽  
Large Time ◽  
Electron Ground State

A coherent state approach is presented to analyze the behavior of a 2D electron subject to an external magnetic field, normal to the plane, in the presence of dissipation. The phenomenon of the shrinking of the Gaussian (localization), describing the electron ground state, takes place on large time scales. Its relation with the transport properties of such a system is then analyzed.

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