This title appears in the Scientific Report :
2002
Please use the identifier:
http://hdl.handle.net/2128/1750 in citations.
Please use the identifier: http://dx.doi.org/10.1088/0029-5515/42/11/306 in citations.
Control of sawteeth and triggering of NTMs with ion cyclotron resonance frequency waves in JET
Control of sawteeth and triggering of NTMs with ion cyclotron resonance frequency waves in JET
A new scenario to delay or prevent neoclassical tearing mode (NTM) onset is presented. By active sawtooth destabilization, short period and low amplitude sawteeth are generated, such that the sawtooth produced NTM seed island is reduced and the threshold normalized plasma pressure for triggering of...
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Personal Name(s): | Westerhof, E. |
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Sauter, O. / Mayoral, I. C. / Howell, D. F. / Mantsinen, M. J. / Nave, M. F. F. / Alper, B. / Angioni, C. / Belo, P. / Buttery, R. J. / Gondhalekar, A. / Hellsten, T. / Hender, T. C. / Johnson, T. / Lamalle, P. / Maraschek, M. E. / McClements, K. G. / Nguyen, C. J. / Pécquet, A. L. / Podda, S. / Rapp, J. / Sharapov, S. E. / Zabiego, M. | |
Contributing Institute: |
Institut für Plasmaphysik; IPP |
Published in: | Nuclear fusion, 42 (2002) S. 1324 - 1334 |
Imprint: |
Vienna
IAEA
2002
|
Physical Description: |
1324 - 1334 |
DOI: |
10.1088/0029-5515/42/11/306 |
Document Type: |
Journal Article |
Research Program: |
Kernfusion und Plasmaforschung |
Series Title: |
Nuclear Fusion
42 |
Subject (ZB): | |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.1088/0029-5515/42/11/306 in citations.
A new scenario to delay or prevent neoclassical tearing mode (NTM) onset is presented. By active sawtooth destabilization, short period and low amplitude sawteeth are generated, such that the sawtooth produced NTM seed island is reduced and the threshold normalized plasma pressure for triggering of NTMs, beta(Nonset), is increased. The scenario has been explored experimentally in the Joint European Torus (JET). Ion cyclotron resonance frequency (ICRF) waves tuned to the 2nd harmonic H-minority resonance have been used for sawtooth control. Whereas ICRF waves generally induce sawtooth stabilization, favouring the triggering of NTMs and reducing beta(Nonset), the present experiments show that by toroidally directed waves, ion cyclotron current drive is produced, and that sawteeth can be destabilized by careful positioning of the 2nd harmonic H resonance layer with respect to the sawtooth inversion radius. As a result, NTM onset is delayed and beta(Nonset) is increased above its value obtained in discharges with additional heating from neutral beam injection alone. |