TY - JOUR

T1 - Observations of rotation in JET plasmas with electron heating by ion cyclotron resonance heating

A1 - Hellsten,T.

A1 - Johnson,T. J.

A1 - Van Eester,D.

A1 - Lerche,E.

A1 - Lin,Y.

A1 - Mayoral,M-L

A1 - Ongena,J.

A1 - Calabro,G.

A1 - Crombe,K.

A1 - Frigione,D.

A1 - Giroud,C.

A1 - Lennholm,M.

A1 - Mantica,P.

A1 - Nave,M. F. F.

A1 - Naulin,Volker

A1 - Sozzi,C.

A1 - Studholme,W.

A1 - Tala,T.

A1 - Versloot,T.

A1 - JET-EFDA Contributors

AU - Hellsten,T.

AU - Johnson,T. J.

AU - Van Eester,D.

AU - Lerche,E.

AU - Lin,Y.

AU - Mayoral,M-L

AU - Ongena,J.

AU - Calabro,G.

AU - Crombe,K.

AU - Frigione,D.

AU - Giroud,C.

AU - Lennholm,M.

AU - Mantica,P.

AU - Nave,M. F. F.

AU - Naulin,Volker

AU - Sozzi,C.

AU - Studholme,W.

AU - Tala,T.

AU - Versloot,T.

AU - JET-EFDA Contributors

PB - Institute of Physics Publishing

PY - 2012

Y1 - 2012

N2 - 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.

AB - 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.

KW - Physics

KW - Alcator c-mode

KW - Impurity toroidal rotation

KW - Ohmic h-mode

KW - Momentum input

KW - TCV tokamak

KW - ICRF

KW - Conversion

KW - Transport

KW - Upgrade

U2 - 10.1088/0741-3335/54/7/074007

DO - 10.1088/0741-3335/54/7/074007

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

SN - 0741-3335

IS - 7

VL - 54

SP - -

ER -