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Title: Observation of a multimode plasma response and its relationship to density pumpout and edge-localized mode suppression

Density pumpout and edge-localized mode (ELM) suppression by applied n=2 magnetic fields in low collisionality DIII-D plasmas are shown to be correlated with the magnitude of the plasma response driven on the high field side (HFS) of the magnetic axis, but not the low-field side (LFS) midplane. These distinct responses are a direct measurement of a multi-modal magnetic plasma response, with each structure preferentially excited by a different n=2 applied spectrum and preferentially detected on the LFS or HFS. Ideal and resistive MHD calculations find that the LFS measurement is primarily sensitive to excitation of stable kink modes, while the HFS measurement is primarily sensitive to resonant currents (whether fully shielding or partially penetrated). Lastly, the resonant currents are themselves strongly modified by kink excitation, with the optimal applied field pitch for pumpout and ELM suppression significantly differing from equilibrium field-alignment.
Authors:
 [1] ;  [2] ;  [3] ;  [2] ;  [1] ;  [1] ;  [4] ;  [1] ;  [1] ;  [5] ;  [2] ;  [2] ;  [6] ;  [2]
  1. General Atomics, San Diego, CA (United States)
  2. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  3. Australian National Univ., Canberra, ACT (Australia)
  4. Columbia Univ., New York, NY (United States)
  5. Univ. of California, San Diego, La Jolla, CA (United States)
  6. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
OSTI Identifier:
1329636
Grant/Contract Number:
FC02-04ER54698
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 114; Journal Issue: 10; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
U.S. Department of Energy, Washington, D.C. (United States)
Sponsoring Org:
USDOE Office of Nuclear Energy (NE)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY