Demonstration of Effective Control of Fast-Ion-Stabilized Sawteeth by Electron-Cyclotron Current Drive

Journal Article · Fri Mar 20 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.102.115004· OSTI ID:21180305

Lennholm, M; Eriksson, L -G; Turco, F; Bouquey, F; Darbos, C; Dumont, R; Giruzzi, G; Jung, M; Lambert, R; Magne, R; Molina, D; Moreau, P; Rimini, F; Segui, J-L; Song, S; Traisnel, E ^[1]

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1. Association EURATOM-CEA, DSM/IRFM, CEA/Cadarache, 13108 St. Paul-lez-Durance (France)

In a tokamak plasma, sawtooth oscillations in the central temperature, caused by a magnetohydrodynamic instability, can be partially stabilized by fast ions. The resulting less frequent sawtooth crashes can trigger unwanted magnetohydrodynamic activity. This Letter reports on experiments showing that modest electron-cyclotron current drive power, with the deposition positioned by feedback control of the injection angle, can reliably shorten the sawtooth period in the presence of ions with energies {>=}0.5 MeV. Certain surprising elements of the results are evaluated qualitatively in terms of existing theory.

• OSTI ID: 21180305
• Journal Information: Physical Review Letters, Vol. 102, Issue 11; Other Information: DOI: 10.1103/PhysRevLett.102.115004; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ECR CURRENT DRIVE
IONS
PLASMA INSTABILITY
SAWTOOTH OSCILLATIONS
TOKAMAK DEVICES