Individual Sawtooth Pacing by Synchronized ECCD in TCV

Journal Article · Fri Dec 23 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3665024· OSTI ID:21612527

Goodman, T P; Felici, F; Canal, G; Duval, B P; Graves, J P; Reimerdes, H; Sauter, O; Testa, D ^[1]

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1. Centre de Recherches en Physique des Plasmas, Ecole Polytechnique Federale de Lausanne (CRPP-EPFL), Lausanne (Switzerland)

Previous real-time sawtooth control scenarios using EC actuators have attempted to shorten or lengthen the sawtooth period by optimally positioning the EC absorption near the q = 1 surface. In new experiments we demonstrate for the first time that individual sawtooth crashes can be repetitively induced at predictable times by reducing the stabilizing ECCD power after a predetermined time from the preceding crash. Other stabilizing actuators (e.g. ICRF, NBI) are expected to produce similar effects. Armed with these results, we present a new sawtooth / NTM control paradigm for improved performance in burning plasmas. The potential appearance of neo-classical tearing modes, triggered by long period sawtooth crashes even at low beta, becomes predictable and therefore amenable to preemptive ECCD. The ITER Electron Cyclotron Upper Launcher (EC-UL) design incorporates the needed functionalities for this method to be applied. The methodology and associated TCV experiments will be presented.

• OSTI ID: 21612527
• Journal Information: AIP Conference Proceedings, Vol. 1406, Issue 1; Conference: 9. topical conference on radio frequency power in plasmas, Newport (United States), 1-3 Jun 2011; Other Information: DOI: 10.1063/1.3665024; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABSORPTION
ACTUATORS
CONTROL
CONTROL SYSTEMS
DESIGN
ECR CURRENT DRIVE
ELECTRONS
ICR HEATING
ION CYCLOTRON-RESONANCE
ITER TOKAMAK
PERFORMANCE
PLASMA
SAWTOOTH OSCILLATIONS
TCV TOKAMAK
TEARING INSTABILITY
CLOSED PLASMA DEVICES
CYCLOTRON RESONANCE
ELEMENTARY PARTICLES
FERMIONS
HEATING
HIGH-FREQUENCY HEATING
INSTABILITY
LEPTONS
NON-INDUCTIVE CURRENT DRIVE
OSCILLATIONS
PLASMA HEATING
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RESONANCE
SORPTION
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS