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

Nuclear Fushion

article

G.J. Choi¹ 

[1] Nuclear Research Institute for Future Technology and Policy, Seoul National University

关键词: gyrokinetics;    tokamak;    magnetic island;    vortex flow;    turbulence;    self-generation;    transport barrier;   

DOI  :  10.1088/1741-4326/accf6b

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

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 ePhi_mathrm{cr}/T = epsilon w/r , whereTis temperature, ε is the inverse aspect ratio andris 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.

【 授权许可】

Unknown