Diffusions and anomalous diffusions of charged particles in the plateau regime of toroidal plasma

TL;DR

This paper investigates the diffusion behaviors of charged particles in toroidal plasma, deriving transport coefficients and analyzing their dependence on plasma parameters, revealing insights into anomalous diffusion mechanisms in plasma physics.

Contribution

It introduces a detailed derivation of diffusion and thermal diffusion tensors in toroidal plasma, highlighting the role of anomalous diffusion coefficients independent of magnetic field strength.

Findings

Diffusion coefficients inversely proportional to the square of gyrofrequency.

Anomalous diffusion coefficients depend on radial position, temperature, and stability factors.

Transport coefficients are influenced by plasma parameters such as collision frequency.

Abstract

The diffusions and anomalous diffusions of charged particles in the plateau regime of toroidal plasma with a Maxwellian velocity distribution are studied. The transport theory of plasma is discussed under the toroidal coordinate system and the magnetic field is assumed to be axisymmetric. Based on the diffusion flux obtained in the toroidal plasma, we derive the diffusion coefficient tensor and thermal diffusion coefficient tensor, where two angular diffusion coefficients are the anomalous diffusions, depending on the radial position and having nothing to do with the magnetic field. All the radial transport coefficients and the normal angular coefficients are inversely proportional to square of the gyrofrequency and so to square of the magnetic induction. The numerical analyses show clearly dependences of these complex transport coefficients on the temperature, the magnetic fluid stability safe factor and the effective collision frequency, respectively.