Kinetic axisymmetric gravitational equilibria in collisionless accretion disk plasmas

Journal Article · Thu Jul 15 04:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3455537· OSTI ID:21389128

Cremaschini, Claudio; Miller, John C ^[1]; Tessarotto, Massimo ^[2]

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1. International School for Advanced Studies (SISSA) and INFN, Trieste 34136 (Italy)
2. Department of Mathematics and Informatics, Trieste University, Trieste 34127 (Italy)

A theoretical treatment is presented of kinetic equilibria in accretion disks (AD) around compact objects, for cases where the plasma can be considered as collisionless. The plasma is assumed to be axisymmetric and to be acted on by gravitational and electromagnetic fields; in this paper, the particular case is considered where the magnetic field admits a family of toroidal magnetic surfaces, which are locally mutually nested and closed. It is pointed out that there exist asymptotic kinetic equilibria represented by generalized bi-Maxwellian distribution functions and characterized by primarily toroidal differential rotation and temperature anisotropy. It is conjectured that kinetic equilibria of this type can exist which are able to sustain both toroidal and poloidal electric current densities, the latter being produced via finite Larmor-radius effects associated with the temperature anisotropy. This leads to the possibility of existence of a new kinetic effect - referred to here as a 'kinetic dynamo effect - resulting in the self-generation of toroidal magnetic field even by a stationary plasma, without any net radial accretion flow being required. The conditions for these equilibria to occur, their basic theoretical features, and their physical properties are all discussed in detail.

• OSTI ID: 21389128
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCRETION DISKS
ANISOTROPY
AXIAL SYMMETRY
COLLISIONLESS PLASMA
DISTRIBUTION FUNCTIONS
ELECTROMAGNETIC FIELDS
ELECTRON TEMPERATURE
EQUILIBRIUM
FUNCTIONS
GRAVITATIONAL FIELDS
ION TEMPERATURE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETIC SURFACES
PLASMA
SYMMETRY