English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Journal Article

Control of sawteeth and triggering of NTMs with ion cyclotron resonance frequency waves in JET

MPS-Authors
/persons/resource/persons108574

Angioni,  C.       
Tokamak Theory (TOK), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons109197

Gondhalekar,  A.
Experimental Plasma Physics 2 (E2), Max Planck Institute for Plasma Physics, Max Planck Society;

/persons/resource/persons109880

Maraschek,  M. E.
Experimental Plasma Physics 2 (E2), Max Planck Institute for Plasma Physics, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Westerhof, E., Sauter, O., Mayoral, M. L., Howell, D. F., Mantsinen, M. J., Nave, M. F. F., et al. (2002). Control of sawteeth and triggering of NTMs with ion cyclotron resonance frequency waves in JET. Nuclear Fusion, 42(11), 1324-1334.


Cite as: https://hdl.handle.net/11858/00-001M-0000-0027-42E2-D
Abstract
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.