Abstract Details
Abstracts
Author: Omar E Lopez
Requested Type: Poster
Submitted: 2019-03-16 23:36:18
Co-authors: L. Guazzotto
Contact Info:
Auburn University
206 Allison Lab
Auburn, Alabama 36849
USA
Abstract Text:
Ideal external kink modes and resistive wall modes are among the most studied MHD instabilities in tokamaks. In regards to analyses including toroidal flow, generally, they either consider rigid rotation and are performed in an analytical (or semi-analytical) way or assume a more realistic, diffuse rotation scenario, and a full numerical approach is taken. Here, we start from an economical, self-consistent, analytic equilibrium for a high-aspect-ratio tokamak with a circular cross-section and a diffuse toroidal angular rotation profile, and reduce the eigenvalue problem to a set of algebraic equations which incorporate a kink mode drive for instabilities and resistive wall effects, while pressure and shear-flow drives are captured at the eigenmode equation level. Solutions are found by a straightforward shooting method for the coupled side-band components and are compared against a sharp-boundary model with a solid-body rotation from the literature [1]. Although, in general, results indicate that the qualitative character of the instabilities under study in the presence of a diffuse or a solid-body rotation are similar, flow has a stronger destabilizing effect in the former model. Arguably, this difference is due to a global shear-flow drive effect.
[1] R. Betti. Phys. Plasmas, 5:3615 (1998).
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