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Title: Non-resonant destabilization of (1/1) internal kink mode by suprathermal electron pressure

New experimental observations are reported on the structure and dynamics of short-lived periodic (1, 1) “fishbone”-like oscillations that appear during radio frequency heating and current-drive experiments in tokamak plasmas. For the first time, measurements can directly relate changes in the high energy electrons to the mode onset, saturation, and damping. In the relatively high collisionality of Alcator C-Mod with lower hybrid current drive, the instability appears to be destabilized by the non-resonant suprathermal electron pressure—rather than by wave-particle resonance, rotates toroidally with the plasma and grows independently of the (1, 1) sawtooth crash driven by the thermal plasma pressure.
Authors:
; ; ; ; ;  [1] ;  [2] ; ; ; ; ; ; ; ; ; ; ; ; ;  [3] more »; « less
  1. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)
  2. MIT - Laboratory of Nuclear Science, Cambridge, Massachusetts 02139 (United States)
  3. MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)
Publication Date:
OSTI Identifier:
22410277
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 5; Other Information: (c) 2015 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; ALCATOR DEVICE; ELECTRONS; HIGH-FREQUENCY HEATING; LOWER HYBRID CURRENT DRIVE; PLASMA INSTABILITY; PLASMA PRESSURE; RADIOWAVE RADIATION; RESONANCE; SAWTOOTH OSCILLATIONS; TIME MEASUREMENT