Bright spots generated by lower hybrid waves on JET

K.M. Rantamäki, V. Petržílka, P. Andrew, I. Coffey, A. Ekedahl, K. Erents, V. Fuchs, M. Goniche, G. Granucci, E. Joffrin, S.J. Karttunen, P. Lomas, J. Mailloux, M. Mantsinen, M.-L. Mayoral, D.C. McDonald, J.-M. Noterdaeme, V. Parail, A.A. Tuccillo, F. Žáček

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Observations of bright spots on the JET divertor aprons during lower hybrid current drive experiments are described. These bright spots are important because they can potentially cause damage to large tokamaks. The bright spots arise due to the impact of a fast particle beam. This beam originates from the front of the lower hybrid launcher, where thermal particles are accelerated according to theory by interaction with the high spatial harmonics of the lower hybrid wave. The bright spots are clearly related to the lower hybrid power as they disappear when the lower hybrid power is switched off. According to the analysis versus various parameters, the brightness of the spots clearly decreases with increasing plasma-wall distance, i.e. the distance between the last closed flux surface and the poloidal limiter. This is clearly beneficial for ITER, as it is designed to operate at a large plasma-wall distance. © 2005 IOP Publishing Ltd.
Original languageEnglish
Pages (from-to)1101 - 1108
Number of pages8
JournalPlasma Physics and Controlled Fusion
Issue number7
Publication statusPublished - 1 Jul 2005
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Nuclear Energy and Engineering
  • Condensed Matter Physics

Cite this

Rantamäki, K. M., Petržílka, V., Andrew, P., Coffey, I., Ekedahl, A., Erents, K., Fuchs, V., Goniche, M., Granucci, G., Joffrin, E., Karttunen, S. J., Lomas, P., Mailloux, J., Mantsinen, M., Mayoral, M-L., McDonald, D. C., Noterdaeme, J-M., Parail, V., Tuccillo, A. A., & Žáček, F. (2005). Bright spots generated by lower hybrid waves on JET. Plasma Physics and Controlled Fusion, 47(7), 1101 - 1108.