Observations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating

TitleObservations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating
Publication TypeJournal Article
Year of Publication2012
AuthorsT. Hellsten, T.J Johnson, D. Van Eester, E. Lerche, Y. Lin, M.L Mayoral, J. Ongena, G. Calabro, K. Crombe, D. Frigione, C. Giroud, M. Lennholm, P. Mantica, MFF Nave, V. Naulin, C. Sozzi, W. Studholme, T. Tala, T. Versloot
JournalPlasma Physics and Controlled Fusion
Volume54
Number7
Pagination074007
Date PublishedJul
Type of ArticleArticle
ISBN Number0741-3335
KeywordsALCATOR C-MOD, CONVERSION, ICRF, IMPURITY TOROIDAL ROTATION, MOMENTUM INPUT, OHMIC H-MODE, TCV TOKAMAK, TRANSPORT, UPGRADE
Abstract

The rotation of L-mode plasmas in the JET tokamak heated by waves in the ion cyclotron range of frequencies (ICRF) damped on electrons, is reported. The plasma in the core is found to rotate in the counter-current direction with a high shear and in the outer part of the plasma with an almost constant angular rotation. The core rotation is stronger in magnitude than observed for scenarios with dominating ion cyclotron absorption. Two scenarios are considered: the inverted mode conversion scenarios and heating at the second harmonic He-3 cyclotron resonance in H plasmas. In the latter case, electron absorption of the fast magnetosonic wave by transit time magnetic pumping and electron Landau damping (TTMP/ELD) is the dominating absorption mechanism. Inverted mode conversion is done in (He-3)-H plasmas where the mode converted waves are essentially absorbed by electron Landau damping. Similar rotation profiles are seen when heating at the second harmonic cyclotron frequency of He-3 and with mode conversion at high concentrations of He-3. The magnitude of the counter-rotation is found to decrease with an increasing plasma current. The correlation of the rotation with the electron temperature is better than with coupled power, indicating that for these types of discharges the dominating mechanism for the rotation is related to indirect effects of electron heat transport, rather than to direct effects of ICRF heating. There is no conclusive evidence that mode conversion in itself affects rotation for these discharges.

URLhttp://iopscience.iop.org/0741-3335/54/7/074007/
DOI10.1088/0741-3335/54/7/074007
Division

FP

Department

PDG

PID

93740712309ac4cdd84e5f589db2cc2f

Alternate TitlePlasma Phys. Control. Fusion

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