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Title: Experimental tests of linear and nonlinear three-dimensional equilibrium models in DIII-D

Journal Article · · Physics of Plasmas
DOI:https://doi.org/10.1063/1.4923017· OSTI ID:22490007
; ; ; ;  [1]; ; ; ; ;  [2];  [3];  [4];  [5];  [6]
  1. General Atomics, P.O. Box 85608, San Diego, California 92816-5608 (United States)
  2. Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States)
  3. Plasma Research Laboratory, Research School of Physical Sciences and Engineering, The Australia National University, Canberra, Australian Capital Territory 0200 (Australia)
  4. Columbia University, 2960 Broadway, New York, New York 10027 (United States)
  5. Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom)
  6. Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States)

DIII-D experiments using new detailed magnetic diagnostics show that linear, ideal magnetohydrodynamics (MHD) theory quantitatively describes the magnetic structure (as measured externally) of three-dimensional (3D) equilibria resulting from applied fields with toroidal mode number n = 1, while a nonlinear solution to ideal MHD force balance, using the VMEC code, requires the inclusion of n ≥ 1 to achieve similar agreement. These tests are carried out near ITER baseline parameters, providing a validated basis on which to exploit 3D fields for plasma control development. Scans of the applied poloidal spectrum and edge safety factor confirm that low-pressure, n = 1 non-axisymmetric tokamak equilibria are determined by a single, dominant, stable eigenmode. However, at higher beta, near the ideal kink mode stability limit in the absence of a conducting wall, the qualitative features of the 3D structure are observed to vary in a way that is not captured by ideal MHD.

OSTI ID:
22490007
Journal Information:
Physics of Plasmas, Vol. 22, Issue 7; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
Country of Publication:
United States
Language:
English

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Cited By (12)

Modal analysis of the full poloidal structure of the plasma response to n = 2 magnetic perturbations journal July 2018
Screening of resonant magnetic perturbation fields by poloidally varying toroidal plasma rotation journal August 2018
Effect of plasma response on the fast ion losses due to ELM control coils in ITER journal March 2016
Equilibrium drives of the low and high field side n   =  2 plasma response and impact on global confinement journal April 2016
Modelling of 3D fields due to ferritic inserts and test blanket modules in toroidal geometry at ITER journal April 2016
ELM control with RMP: plasma response models and the role of edge peeling response journal October 2016
Dynamics of ideal modes and subsequent ELM crashes in 3D tokamak geometry from external magnetic perturbations journal November 2018
Numerical survey of predicted peeling response in edge localised mode mitigated and suppressed phases on ASDEX upgrade journal August 2019
Effects of the applied magnetic fields with various toroidal phase differences on the neoclassical toroidal viscosity in JT-60SA journal October 2018
Magnetic polarization measurements of the multi-modal plasma response to 3D fields in the EAST tokamak journal May 2018
Resistive versus ideal plasma response to RMP fields in DIII-D: roles of q 95 and X-point geometry journal June 2019
ELM control with RMP: plasma response models and the role of edge peeling response text January 2016