On the existence of Weibel instability in a magnetized plasma. I. Parallel wave propagation

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3072976· OSTI ID:21272448

Lazar, M ^[1]; Schlickeiser, R ^[2]; Poedts, S ^[1]

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1. Center for Plasma Astrophysics, Celestijnenlaan 200B, 3001 Leuven (Belgium)
2. Institut fuer Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

In a uniform static magnetic field (B{sub 0}) the nonresonant mechanism of Weibel instability is certainly affected, because the free energy stored in the temperature anisotropy (e.g., T{sub perpendicular}>T{sub parallel}), where perpendicular and parallel denote directions relative to the background magnetic field) can drive the parallel whistler instability due to the cyclotron resonance with plasma particles. However, it has already been shown that the nonresonant mechanism should exist and drive the whistler instability, at least, for anisotropic distribution functions with no parallel thermal velocity spread. Here the investigation is extended to a magnetized plasma with a bi-Maxwellian temperature anisotropy. New frequency limits are introduced and the necessary physical conditions are provided: The nonresonant whistler instabilities have in general small frequencies, smaller than the growth rate, {omega}{sub r}<{omega}{sub i}, and for a large temperature anisotropy, the nonresonant instabilities are limited to a {beta}{sub perpendicular}=8{pi}n{sub 0}T{sub perpendicular}/B{sub 0}{sup 2}>1 regime. These criteria restricts in general the magnetic field to strengths less than a threshold value proportional to the square root of the temperature anisotropy. In the presence of an ambient magnetic field, the growth rate of the nonresonant instability is reduced and the large wavelengths are stabilized.

• OSTI ID: 21272448
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 1 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANISOTROPY
DISTRIBUTION FUNCTIONS
ELECTRON TEMPERATURE
ION TEMPERATURE
MAGNETIC FIELDS
PLASMA
WAVE PROPAGATION
WHISTLER INSTABILITY