Demonstration of Effective Control of Fast-Ion-Stabilized Sawteeth by Electron-Cyclotron Current DriveFunded under: FP7-EURATOM
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.
Bibliographic Reference: An article published in: Physical Review Letters, Volume 102 (2009), 4 pp.
Availability: This article can be accessed online by subscribers, and can be ordered online by non-subscribers, at: http://dx.doi.org/10.1103/PhysRevLett.102.115004
Record Number: 200910387 / Last updated on: 2009-09-22
Original language: en
Available languages: en