Perturbative studies of toroidal momentum transport using neutral beam injection modulation in the Joint European Torus: Experimental results, analysis methodology, and first principles modelling
Journal article, 2010
Perturbative experiments have been carried out in the Joint European Torus [Fusion Sci. Technol. 53(4) (2008)] in order to identify the diffusive and convective components of toroidal momentum transport. The torque source was modulated either by modulating tangential neutral beam power or by modulating in antiphase tangential and normal beams to produce a torque perturbation in the absence of a power perturbation. The resulting periodic perturbation in the toroidal rotation velocity was modeled using time-dependent transport simulations in order to extract empirical profiles of momentum diffusivity and pinch. Details of the experimental technique, data analysis, and modeling are provided. The momentum diffusivity in the core region (0.2 < ρ < 0.8) was found to be close to the ion heat diffusivity ( φ / i ∼0.7-1.7) and a significant inward momentum convection term, up to 20 m/s, was found, leading to an effective momentum diffusivity significantly lower than the ion heat diffusivity (χ φ eff /χ i eff ∼0.4). These results have significant implications on the prediction of toroidal rotation velocities in future tokamaks and are qualitatively consistent with recent developments in momentum transport theory. Detailed quantitative comparisons with the theoretical predictions of the linear gyrokinetic code GKW [A. G. Peeters, Comput. Phys. Commun. 180, 2650 (2009)] and of the quasilinear fluid Weiland model [J. Weiland, Collective Modes in Inhomogeneous Plasmas (IOP, Bristol, 2000)] are presented for two analyzed discharges. © 2010 EURATOM.
Transport Tokamak Moment
Author
P Mantica
ENEA
EFDA-JET
T Tala
Technical Research Centre of Finland (VTT)
EFDA-JET
J. Ferreira
EFDA-JET
Instituto Superior Tecnico
A. G. Peeters
The University of Warwick
EFDA-JET
A. Salmi
EFDA-JET
Aalto University
D. Strintzi
National Technical University of Athens (NTUA)
EFDA-JET
Jan Weiland
Chalmers, Department of Radio and Space Science, Transport Theory
Brix, M
Culham Science Centre
EFDA-JET
C Giroud
EFDA-JET
Culham Science Centre
G Corrigan
EFDA-JET
Culham Science Centre
V Naulin
Technical University of Denmark (DTU)
EFDA-JET
G. Tardini
Max Planck Society
EFDA-JET
K. D. Zastrow
EFDA-JET
Culham Science Centre
Physics of Plasmas
1070-664X (ISSN) 1089-7674 (eISSN)
Vol. 17 9 092505- 092505Subject Categories
Physical Sciences
Fusion, Plasma and Space Physics
DOI
10.1063/1.3480640