Gyrokinetic theory for particle transport in fusion plasmas

TL;DR

This paper develops a comprehensive set of gyrokinetic equations to describe particle and energy transport in fusion plasmas, incorporating magnetic geometry effects without assuming scale separation, enabling more accurate modeling of turbulent and collisional transport.

Contribution

It derives transport equations directly from kinetic theory using gyrokinetics, avoiding the scale separation assumptions of previous models.

Findings

Equations describe transport on the energy confinement time scale.

Explicitly includes magnetic field geometry effects.

Allows self-consistent study of turbulence and collisions.

Abstract

A set of equations is derived describing the macroscopic transport of particles and energy in a thermonuclear plasma on the energy confinement time. The equations thus derived allow studying collisional and turbulent transport self-consistently, retaining the effect of magnetic field geometry without postulating any scale separation between the reference state and fluctuations. Previously, assuming scale separation, transport equations have been derived from kinetic equations by means of multiple-scale perturbation analysis and spatio-temporal averaging. In this work, the evolution equations for the moments of the distribution function are obtained following the standard approach; meanwhile, gyrokinetic theory has been used to explicitly express the fluctuation induced fluxes. In this way, equations for the transport of particles and energy up to the transport time scale can be derived using standard first order gyrokinetics.