Ubiquity of non-diffusive momentum transport in JET H-modes

TitleUbiquity of non-diffusive momentum transport in JET H-modes
Publication TypeJournal Article
Year of Publication2012
AuthorsH. Weisen, Y. Camenen, A. Salmi, T.W Versloot, P.C de Vries, M. Maslov, T. Tala, M. Beurskens, C. Giroud, JET-EFDA Contributors
JournalNuclear Fusion
Volume52
Number11
Pagination114024
Abstract

A broad survey of the experimental database of neutral beam heated baseline H-modes and hybrid scenarios in the JET tokamak has established the ubiquity of non-diffusive momentum transport mechanisms in rotating plasmas. As a result of their presence, the normalized angular frequency gradient R ∇ ω / ω is higher than expected from momentum diffusion alone, by about unity in the core ( r / a ∼ 0.3), rising to near 5 close to the edge, where its contribution to the total gradient is comparable to the gradient associated with the diffusive flux. The magnitude and parameter dependences of the non-diffusive contribution to the gradient are consistent with a theoretically expected pinch, which has its origin in the vertical particle drift resulting from the Coriolis force. Linear gyrokinetic calculations of the pinch number RV / χ φ and the Prandtl number χ φ / χ i are in good agreement with the experimental observations, with similar dependences on R / L n , q and ε = r / R . A contribution due to residual stresses may also be present, but could not be identified with certainty.

URLhttp://www.iop.org/Jet/article?EFDP11051&EFDP11055
DOI10.1088/0029-5515/52/11/114024
Division

FP

Department

PDG

PID

4b4ec77675b7d97300fd63aed60dd6e8

Alternate TitleNucl. Fusion
LabelOA

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