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Title: Measurement of 3D plasma response to external magnetic perturbations in the presence of a rotating external kink

The detailed measurements of the 3D plasma response to applied external magnetic perturbations in the presence of a rotating external kink are presented, and compared with the predictions of a single-helicity linear model of kink mode dynamics. The modular control coils of the High Beta Tokamak-Extended Pulse (HBT-EP) device are used to apply resonant m/n = 3/1 magnetic perturbations to wall-stabilized tokamak plasmas with a pre-existing rotating 3/1 kink mode. The plasma response is measured in high-resolution with the extensive magnetic diagnostic set of the HBT-EP device. The spatial structures of both the naturally rotating kink mode and the externally driven response are independently measured and observed to be identical, while the temporal dynamics are consistent with the independent evolution and superposition of the two modes. This leads to the observation of a characteristic change in 3D field dynamics as a function of the applied field amplitude. This amplitude dependence is found to be different for poloidal and radial fields. The measured 3D response is compared to and shown to be consistent with the predictions of the linear single-helicity model in the “high-dissipation” regime, as reported previously [M. E. Mauel et al., Nucl. Fusion 45, 285 (2005)].
Authors:
; ; ; ; ; ; ; ; ; ;  [1] ;  [2] ;  [3]
  1. Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)
  2. Physics Department, Auburn University, Auburn, Alabama 36849 (United States)
  3. Tri Alpha Energy, Rancho Santa Margarita, California 92688 (United States)
Publication Date:
OSTI Identifier:
22218528
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 10; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; COLUMBIA HIGH-BETA TOKAMAK; COMPARATIVE EVALUATIONS; DISTURBANCES; HELICITY; HIGH-BETA PLASMA; KINK INSTABILITY; MAGNETOHYDRODYNAMICS; PLASMA CONFINEMENT; PLASMA DIAGNOSTICS; WALL EFFECTS