Fast ions in mode conversion heating (

V.G. Kiptily, D. Van Eester, E. Lerche, T. Hellsten, J. Ongena, M.-L. Mayoral, F.E. Cecil, D. Darrow, M. Gatu Johnson, V. Goloborod'Ko, G. Gorini, C. Hellesen, T. Johnson, Y. Lin, M. Maslov, M. Nocente, M. Tardocchi, I. Voitsekhovitch

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Abstract

Fast ions were analysed in experiments focusing on fundamental3He minority and mode conversion (MC) in the ion cyclotron resonance range of frequencies (ICRF) in H plasmas and on second harmonic heating of3He ions at 2.65T mimicking D-T plasma heating in ITER at half its nominal toroidal magnetic field. Gamma-ray spectrometry, neutral particle analysers and fast-ion loss diagnostics provided information on the generation of fast-ion populations and on the distribution of ICRH power among the species in various heating scenarios and for a large range of3He concentrations. In the scenario with the fundamental3He minority and MC wave heating at BT(0)=3.41T and f32MHz, fast3He ions accelerated by ICRH in the MeV energy range were detected in discharges with low3He concentration. In the experiments with a3He concentration scan it was found that at a3He concentration of 2.2% the3He ion losses disappeared while a population of energetic D ions gradually built up due to a redistribution of the ICRH power between species on reaching the first MC regime. Under those conditions the ICRF-heated D beam ions effectively absorbed the wave power at their Doppler shifted resonance, which was close to the plasma centre. In discharges with second harmonic heating of3He ions at BT(0)=2.65T and f52MHz, the confined energetic3He ions were found in the MeV energy range. There is some evidence that the D ions were also accelerated by ICRF. This paper also demonstrates that the synergy of the various fast ion diagnostics allows making a broad picture of the physics of the redistribution of the absorbed ICRH power in complicated heating scenarios of JET. © 2012 IOP Publishing Ltd.
Original languageEnglish
Article number074010
Pages (from-to)-
JournalPlasma Physics and Controlled Fusion
Volume54
Issue number7
DOIs
Publication statusPublished - Jul 2012
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Nuclear Energy and Engineering
  • Condensed Matter Physics

Cite this

Kiptily, V. G., Van Eester, D., Lerche, E., Hellsten, T., Ongena, J., Mayoral, M-L., ... Voitsekhovitch, I. (2012). Fast ions in mode conversion heating (. Plasma Physics and Controlled Fusion, 54(7), -. [074010]. https://doi.org/10.1088/0741-3335/54/7/074010