Self-generated vortex flows in a tokamak magnetic island with a background flow

Abstract We present a gyrokinetic theory of self-generated E × B vortex flows in a magnetic island in a collisionless tokamak plasma with a background vortex flow. We find that the long-term evolution of the self-generated vortex flows can be classified into two regimes by the background vortex flow...

Full description

Saved in:
Bibliographic Details
Published inNuclear fusion Vol. 63; no. 6; pp. 66032 - 66042
Main Author Choi, G.J.
Format Journal Article
LanguageEnglish
Published IOP Publishing 01.06.2023
Subjects
gyrokinetics
magnetic island
self-generation
tokamak
transport barrier
turbulence
vortex flow
Online AccessGet full text

Cover

More Information
Summary:Abstract We present a gyrokinetic theory of self-generated E × B vortex flows in a magnetic island in a collisionless tokamak plasma with a background vortex flow. We find that the long-term evolution of the self-generated vortex flows can be classified into two regimes by the background vortex flow potential Φ, with an asymptotic criterion given by e Φ c r / T = ϵ w / r , where T is temperature, ε is the inverse aspect ratio and r is the radial coordinate. We find that the background vortex flow above the criterion significantly weakens the toroidal precession-induced long-term damping and structure change of the self-generated vortex flows. That is, the finite background vortex flow is beneficial to maintain the self-generated vortex flows, favorable to an internal transport barrier formation. Our result indicates that the island boundary region is a prominent location for triggering the transition to an enhanced confinement state of the magnetic island.
Bibliography:NF-105973.R2
ISSN:0029-5515
1741-4326
DOI:10.1088/1741-4326/accf6b