Abstract Details
Abstracts
Author: Alejandro Banon Navarro
Requested Type: Poster
Submitted: 2017-03-09 16:23:22
Co-authors: L. Bardoczi, T. A. Carter, T. L. Rhodes, and F. Jenko
Contact Info:
University of California Los Angeles
475 Portola Plaza
Los Angeles, CA 90095
USA
Abstract Text:
Neoclassical Tearing Modes (NTMs) are large-scale magnetohydrodynamic instabilities which form magnetic islands on rational surfaces of tokamaks. NTMs can lead to the degradation of plasma confinement and if they grow large enough, they may lead to plasma termination.
In this context, we will present recent results published in a PPCF special issue dedicated to comparisons of GK simulations with measurements [1], where we investigated the effect of magnetic islands on profiles, flows, turbulence and transport and the scaling of these effects with respect to island size using GENE nonlinear flux-tube simulations. The main results are summarized as follows: (1) There is a clear transition point, below which the islands have little to no effect on turbulence, while beyond this point the islands significantly perturb flows, increase turbulence and transport. (2) Gradients, turbulence as well as cross-field transport levels progressively decrease at the O-point as the island width is increased, in qualitative agreement with recent DIII-D experiments [2].
[1] A. B. Navarro, et al., Plasma Physics and Controlled Fusion 59, 034004 (2017)
[2] L. Bardózci et al., Physical Review Letters 116, 215001 (2016)
Comments: