Ion cyclotron range of frequency mode conversion flow drive in D(He-3) plasmas on JET

TitleIon cyclotron range of frequency mode conversion flow drive in D(He-3) plasmas on JET
Publication TypeJournal Article
Year of Publication2012
AuthorsY. Lin, P. Mantica, T. Hellsten, V. Kiptily, E. Lerche, MFF Nave, J.E Rice, D. Van Eester, P.C de Vries, R. Felton, C. Giroud, T. Tala
JournalPlasma Physics and Controlled Fusion
Volume54
Issue7
Pagination074001
Date PublishedJul
Type of ArticleArticle
ISBN Number0741-3335
KeywordsABSORPTION, ALCATOR C-MOD, DIII-D, DISCHARGES, ICRF, NUMERICAL-SIMULATION, TOKAMAK PLASMAS, TOROIDAL ROTATION, TRANSPORT, WAVES
Abstract

Ion cyclotron range of frequency (ICRF) mode conversion has been shown to drive toroidal flow in JET D(He-3) L-mode plasmas: B-t0 = 3.45 T, n(e0) similar to 3x10(19) m(-3), I-p = 2.8 and 1.8 MA, P-RF <= 3MW at 33MHz and -90 degrees phasing. Central toroidal rotation in the counter-I-p direction, with omega(phi 0) up to 10 krad s(-1) (V-phi 0 similar to 30 km s(-1), central thermal Mach number M-th(0) similar to 0.07 and Alfven Mach number M-A(0) similar to 0.003) has been observed. The flow drive effect is sensitive to the He-3 concentration and the largest rotation is observed in the range X[He-3] = n(He3)/n(e) similar to 10-17%. The rotation profile is peaked near the magnetic axis, and the central rotation scales with the input RF power. The effective torque density profile from the RF power has been calculated and the total torque is estimated to be as high as 50% of the same power from neutral beam injection, and a factor of 5 larger than the direct momentum injection from the RF waves. RF physics modeling using the TORIC code shows that the interaction between the mode converted ion cyclotron wave and the He-3 ions, and associated asymmetry in space and momentum, may be key for flow drive.

URLhttp://www.iop.org/Jet/article?EFDP10051&EFDP10053
DOI10.1088/0741-3335/54/7/074001
Division

FP

Department

PDG

PID

14434e31d2b854e120c6b789195cc66d

Alternate TitlePlasma Phys. Control. Fusion
LabelOA

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