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

Journal Article · Fri May 15 00:00:00 EDT 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4919964· OSTI ID:22410277

Delgado-Aparicio, L.; Gates, D. A.; Gorelenkov, N.; Scott, S.; Bertelli, N.; Wilson, R. ^[1]; Sugiyama, L. ^[2]; Shiraiwa, S.; Irby, J.; Granetz, R.; Parker, R.; Baek, S. G.; Faust, I.; Wallace, G.; Mumgaard, R.; Gao, C.; Greenwald, M.; Hubbard, A.; Hughes, J.; Marmar, E. ^[3] ; others, and

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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)

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.

• OSTI ID: 22410277
• Journal Information: Physics of Plasmas, Vol. 22, Issue 5; 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

Related Subjects

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