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Title: Nonlinear MHD simulations of Quiescent H-mode plasmas in DIII-D

In the Quiescent H-mode (QH-mode) regime, the edge harmonic oscillation (EHO), thought to be a saturated kink-peeling mode (KPM) driven unstable by current and rotation, is found in experiment to provide sufficient stationary edge particle transport to avoid the periodic expulsion of particles and energy by edge localized modes (ELMs). In this article, both linear and nonlinear MHD modelling of QH-mode plasmas from the DIII-D tokamak have been investigated to understand the mechanism leading to the appearance of the EHO in QH-mode plasmas. For the first time nonlinear MHD simulations with low-n modes both with ideal wall and resistive wall boundary conditions have been carried out with 3-D non-linear MHD code JOREK. The results show, in agreement with the original conjectures, that in the nonlinear phase, kink peeling modes are the main unstable modes in QH-mode plasmas of DIIID and that the kink-peeling modes saturate non-linearly leading to a 3-D stationary state. The characteristics of the kink-peeling modes, in terms of mode structure and associated decrease of the edge plasma density associated with them, are in good agreement with experimental measurements of the EHO in DIII-D. Finally, the effect of plasma resistivity, the role of plasma parallel rotation as wellmore » as the effect of the conductivity of the vacuum vessel wall on the destabilization and saturation of kink-peeling modes have been evaluated for experimental QH-mode plasma conditions in DIII-D.« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [2] ;  [4] ;  [5]
  1. ITER Organization, St. Paul Lez Durance (France)
  2. General Atomics, San Diego, CA (United States)
  3. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  4. Max Planck Inst. for Plasma Physics, Garching (Germany)
  5. Univ. of California, Los Angeles, CA (United States)
Publication Date:
Grant/Contract Number:
FC02-04ER54698; AC02-09CH11466
Type:
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 55; Journal Issue: 11; Journal ID: ISSN 0029-5515
Publisher:
IOP Science
Research Org:
General Atomics, San Diego, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY JOREK; QH-mode; DIII-D; ELM control
OSTI Identifier:
1375950
Alternate Identifier(s):
OSTI ID: 1375950