Prediction of Nonlinear Evolution Character of Energetic-Particle-Driven Instabilities
Plasma Physics
2017-04-05 v1
Abstract
A general criterion is proposed and found to successfully predict the emergence of chirping oscillations of unstable Alfv\'enic eigenmodes in tokamak plasma experiments. The model includes realistic eigenfunction structure, detailed phase-space dependences of the instability drive, stochastic scattering and the Coulomb drag. The stochastic scattering combines the effects of collisional pitch angle scattering and micro-turbulence spatial diffusion. The latter mechanism is essential to accurately identify the transition between the fixed-frequency mode behavior and rapid chirping in tokamaks and to resolve the disparity with respect to chirping observation in spherical and conventional tokamaks.
Keywords
Cite
@article{arxiv.1610.05059,
title = {Prediction of Nonlinear Evolution Character of Energetic-Particle-Driven Instabilities},
author = {Vinicius Duarte and Herbert Berk and Nikolai Gorelenkov and William Heidbrink and Gerrit Kramer and Raffi Nazikian and David Pace and Mario Podesta and Benjamin Tobias and Michael Van Zeeland},
journal= {arXiv preprint arXiv:1610.05059},
year = {2017}
}