Progress in controlling ICRF-edge interactions in ASDEX upgrade

Journal Article · Thu Dec 10 00:00:00 EST 2015 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4936469· OSTI ID:22496182

Ochoukov, R.; Bilato, R.; Braun, F.; Carralero, D.; Dux, R.; Faugel, H.; Fünfgelder, H.; Jacquot, J.; Lunt, T.; Potzel, S.; Pütterich, Th. ^[1]; Jacquet, Ph.; Monakhov, I. ^[2]; Zhang, W.; Noterdaeme, J. -M.; Stepanov, I. ^[1]; Colas, L.; Meyer, O. ^[3]; Czarnecka, A. ^[4]; others, and

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1. Max-Planck-Institut für Plasmaphysik, Boltzmannstr.2, D-85748 (Germany)
2. CCFE, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)
3. CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)
4. Institute of Plasma Physics and Laser Microfusion, Hery 23 Str., 01-497 Warsaw (Poland)

RF measurements during variation of the strap voltage balance of the original 2-strap ICRF antenna in ASDEX Upgrade at constant power are consistent with electromagnetic calculations by HFSS and TOPICA, more so for the latter. RF image current compensation is observed at the antenna limiters in the experiment at a local strap voltage of about half of the value of the remote strap, albeit with a non-negligible uncertainty in phasing. The RF-specific tungsten (W) source at the broad-limiter 2-strap antenna correlates strongly with the RF voltage at the local strap at the locations not connected to opposite side of the antenna along magnetic field lines. The trends of the observed increase of the RF loading with injection of local gas are well described by a combined EMC3-Eirene – FELICE calculations, with the most efficient improvement confirmed for the outer-midplane valves, but underestimated by about 1/3. The corresponding deuterium density tailoring is also likely responsible for the decrease of local W sources observed in the experiment.

• OSTI ID: 22496182
• Journal Information: AIP Conference Proceedings, Vol. 1689, Issue 1; Conference: 21. topical conference on radio frequency power in plasmas, Lake Arrowhead, CA (United States), 27-29 Apr 2015; Other Information: (c) 2015 EURATOM; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTENNAS
ASDEX TOKAMAK
BALANCES
DENSITY
DEUTERIUM
ELECTRIC POTENTIAL
HYPERFINE STRUCTURE
ICR HEATING
IMAGES
INJECTION
ION CYCLOTRON-RESONANCE
MAGNETIC FIELDS
RADIOWAVE RADIATION
TUNGSTEN
VALVES