Kinetic theory of quasistationary collisionless axisymmetric plasmas in the presence of strong rotation phenomena
Abstract
The problem of formulating a kinetic treatment for quasistationary collisionless plasmas in axisymmetric systems subject to the possibly independent presence of local strong velocityshear and supersonic rotation velocities is posed. The theory is developed in the framework of the VlasovMaxwell description for multispecies nonrelativistic plasmas. Applications to astrophysical accretion discs arising around compact objects and to plasmas in laboratory devices are considered. Explicit solutions for the equilibrium kinetic distribution function (KDF) are constructed based on the identification of the relevant particle adiabatic invariants. These are shown to be expressed in terms of generalized nonisotropic Gaussian distributions. A suitable perturbative theory is then developed which allows for the treatment of nonuniform strong velocityshear/supersonic plasmas. This yields a series representation for the equilibrium KDF in which the leadingorder term depends on both a finite set of fluid fields as well as on the gradients of an appropriate rotational frequency. Constitutive equations for the fluid number density, flow velocity, and pressure tensor are explicitly calculated. As a notable outcome, the discovery of a new mechanism for generating temperature and pressure anisotropies is pointed out, which represents a characteristic feature of plasmas considered here. This is shown to arise as a consequence of the canonical momentum conservation and to contribute to the occurrence of temperature anisotropy in combination with the adiabatic conservation of the particle magnetic moment. The physical relevance of the result and the implications of the kinetic solution for the selfgeneration of quasistationary electrostatic and magnetic fields through a kinetic dynamo are discussed.
 Publication:

Physics of Plasmas
 Pub Date:
 May 2013
 DOI:
 10.1063/1.4807037
 Bibcode:
 2013PhPl...20e2905C
 Keywords:

 Gaussian distribution;
 perturbation theory;
 plasma kinetic theory;
 plasma magnetohydrodynamics;
 plasma temperature;
 shear flow;
 supersonic flow;
 Vlasov equation;
 52.25.Dg;
 52.30.Cv;
 02.50.Ng;
 Plasma kinetic equations;
 Magnetohydrodynamics;
 Distribution theory and Monte Carlo studies