Features of ion acoustic waves in collisional plasmas

Journal Article · Mon Feb 15 04:00:00 EST 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3309490· OSTI ID:21347109

Vranjes, J; Poedts, S ^[1]

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1. Centre for Plasma Astrophysics and Leuven Mathematical Modeling and Computational Science Centre (LMCC), K.U. Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium)

The effects of friction on the ion acoustic (IA) wave in fully and partially ionized plasmas are studied. In a quasineutral electron-ion plasma the friction between the two species cancels out exactly and the wave propagates without any damping. If the Poisson equation is used instead of the quasineutrality, however, the IA wave is damped and the damping is dispersive. In a partially ionized plasma, the collisions with the neutrals modify the IA wave beyond recognition. For a low density of neutrals the mode is damped. Upon increasing the neutral density, the mode becomes first evanescent and then reappears for a still larger number of neutrals. A similar behavior is obtained by varying the mode wavelength. The explanation for this behavior is given. In an inhomogeneous plasma placed in an external magnetic field, and for magnetized electrons and unmagnetized ions, the IA mode propagates in any direction and in this case the collisions make it growing on the account of the energy stored in the density gradient. The growth rate is angle dependent. A comparison with the collisionless kinetic density gradient driven IA instability is also given.

• OSTI ID: 21347109
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGED PARTICLES
COLLISIONAL PLASMA
COLLISIONS
DIFFERENTIAL EQUATIONS
ELECTRONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
INHOMOGENEOUS PLASMA
ION ACOUSTIC WAVES
ION WAVES
IONS
LEPTONS
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
PLASMA WAVES
POISSON EQUATION