@inproceedings{5112e23f314d401ba436bc89bff52180,
title = "Measurements of critical gradient behavior of fast-ion transport from Alfv{\'e}n eigenmodes for predictive model development",
abstract = "Experiments in the DIII-D tokamak show that many overlapping small-amplitude Alfv{\'e}n eigenmodes (AEs) cause fast-ion transport that is consistent with the critical gradient paradigm. Measurements indicate a sudden increase in fast-ion transport in the presence of many simultaneous AEs at a threshold in neutral beam power corresponding to a threshold for orbit stochasticity [1]. The threshold varies in fast-ion phase space and is well above the AE linear stability threshold, meaning that some AEs can be tolerated before performance-degrading transport occurs. Above threshold, transport becomes stiff, resulting in virtually unchanged fast-ion density profiles despite increased beam drive. These studies are being used to develop a validated, predictive transport model that can efficiently calculate AE-induced transport and the resulting fast-ion profile over a wide parameter regime in order to design optimal fusion reactor scenarios that avoid undesirable AE-transport.",
author = "Collins, {C. S.} and Heidbrink, {W. W.} and M. Podest{\`a} and White, {R. B.} and Kramer, {G. J.} and Pace, {D. C.} and Petty, {C. C.} and L. Stagner and {Van Zeeland}, {M. A.} and Zhu, {Y. B.}",
note = "Publisher Copyright: {\textcopyright} 2017 IOP Publishing Ltd.; 44th European Physical Society Conference on Plasma Physics, EPS 2017 ; Conference date: 26-06-2017 Through 30-06-2017",
year = "2017",
language = "English",
isbn = "9781510849303",
series = "44th EPS Conference on Plasma Physics, EPS 2017",
publisher = "European Physical Society (EPS)",
editor = "A. Bret and M. Fajardo and E. Westerhof and A. Melzer and B. Dromey and C. Riconda",
booktitle = "44th EPS Conference on Plasma Physics, EPS 2017",
}