Velocity shear generated Alfv{acute e}n waves in electron{endash}positron plasmas

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.871945· OSTI ID:383773

Rogava, A D ^[1]; Mahajan, S M ^[2]; Berezhiani, V I ^[3]

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1. Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia)
2. Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712 (United States)
3. Department of Plasma Physics, Institute of Physics, The Georgian Academy of Science, Tbilisi 380077, The Republic of (Georgia)

Linear magnetohydrodynamic (MHD) modes in a cold, nonrelativistic electron{endash}positron plasma shear flow are considered. The general set of differential equations, describing the evolution of perturbations in the framework of the nonmodal approach is derived. It is found, that under certain circumstances, the compressional and shear Alfv{acute e}n perturbations may exhibit large transient growth fueled by the mean kinetic energy of the shear flow. The velocity shear also induces mode coupling, allowing the exchange of energy as well as the possibility of a strong mutual transformation of these modes into each other. The compressional Alfv{acute e}n mode may extract the energy of the mean flow and transfer it to the shear Alfv{acute e}n mode via this coupling. The relevance of these new physical effects to provide a better understanding of the laboratory {ital e}{sup +}{ital e}{sup {minus}} plasmas is emphasized. It is speculated that the shear-induced effects in the electron{endash}positron plasmas could also help solve some astrophysical puzzles (e.g., the generation of pulsar radio emission). Since most astrophysical plasmas are relativistic, it is shown that the major results of the study remain valid for weakly sheared relativistic plasmas. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: Univesity of Texas
• DOE Contract Number: FG03-96ER54346
• OSTI ID: 383773
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 3; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ALFVEN WAVES
COLD PLASMA
EARTH MAGNETOSPHERE
ELECTRON GAS
ELECTRON-POSITRON INTERACTIONS
HYDROMAGNETIC WAVES
MAGNETOHYDRODYNAMICS
POSITRONS
RELATIVISTIC PLASMA
SHEAR FLOW