Nave, M. F. F.
[Author];
Koslowski, H. R.
[Author];
Coda, J. W.
[Author];
Graves, J.
[Author];
Buttery, R.
[Author];
Challis, C.
[Author];
Giroud, C.
[Author];
Stamp, M.
[Author];
de Vries, P.
[Author]
Exploring a small sawtooth regime in Joint European Torus plasmas with counterinjected neutral beams
You can manage bookmarks using lists, please log in to your user account for this.
Media type:
E-Article
Title:
Exploring a small sawtooth regime in Joint European Torus plasmas with counterinjected neutral beams
Contributor:
Nave, M. F. F.
[Author];
Koslowski, H. R.
[Author];
Coda, J. W.
[Author];
Graves, J.
[Author];
Buttery, R.
[Author];
Challis, C.
[Author];
Giroud, C.
[Author];
Stamp, M.
[Author];
de Vries, P.
[Author]
imprint:
American Institute of Physics, 2006
Published in:Physics of plasmas 13, 014503 (2006). doi:10.1063/1.2162528
Language:
English
DOI:
https://doi.org/10.1063/1.2162528
ISSN:
1070-664X
Keywords:
Origination:
Footnote:
Diese Datenquelle enthält auch Bestandsnachweise, die nicht zu einem Volltext führen.
Description:
During a recent reversed toroidal field (B-T) campaign at the Joint European Torus (JET), experiments were performed to investigate the effect on sawteeth of neutral beam injection (NBI)-driven toroidal plasma rotation counter to the direction of the toroidal plasma current and B-T. A power scan at constant density has permitted analytical continuation, into the reversed B-T domain, of previous experiments with forward field and hence corotation. Earlier JET results were confirmed, indicating that counter-NBI results in sawtooth periods shorter than in the Ohmic regime. This study has demonstrated that, whereas with co-NBI the sawtooth period increases with power, with counter-NBI the sawtooth period initially decreases with power passing through a minimum at 4 MW. Clearly this trend also manifests itself in terms of the toroidal plasma rotation, for which a minimum is observed for counter-rotation frequency similar to 3 kHz. Sawteeth smaller than Ohmic sawteeth are found to be easier to obtain with perpendicular counter-NBI, for which heating penetrates deeper into the core. The sign and magnitude of the toroidal rotation, the penetration of heating to the electrons, and the peaking of the fast-ion pressure profile in the core may all play an important role in modifying the sawtooh period. (c) 2006 American Institute of Physics.