Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore

Oosako, T; Ekedahl, A; Goniche, M; Achard, J; Decker, J; Peysson, Y

doi:10.1063/1.3664969

Title: Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore

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Abstract

The density fluctuations, modified by Lower Hybrid Wave (LHW), is analyzed in Tore Supra with reference to the injected LHW power, density and the gap between LCFS (Last Closed Flux Surface) and the PAM (passive-active-multijunction) launcher. The density fluctuations are measured with RF probes installed at the PAM launcher front. A density scan at nominal toroidal field (3.8 T) shows that the fluctuations rate stays nearly constant ({approx}50%) for <n{sub e}><3.5x10{sup 19}m{sup -3} and with LHW power up to 2MW. However, when increasing the density above <n{sub e}><{approx}4.2x10{sup 19}m{sup -3}, using strong gas puffing, the fluctuation rate increases to >70% and is characterized by strong negative spikes, with typical frequency >100kHz. These are most likely originating from acceleration of electrons in the LHW near field due to parasitic absorption, as evidenced on the IR images, showing hot spots on the side limiters.

Authors:

Oosako, T; Ekedahl, A; Goniche, M; Achard, J; Decker, J; Peysson, Y ^[1]

CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)

Publication Date:: Fri Dec 23 00:00:00 EST 2011

OSTI Identifier:: 21612484

Resource Type:: Journal Article

Journal Name:: AIP Conference Proceedings

Additional Journal Information:: Journal Volume: 1406; Journal Issue: 1; Conference: 9. topical conference on radio frequency power in plasmas, Newport (United States), 1-3 Jun 2011; Other Information: DOI: 10.1063/1.3664969; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ABSORPTION; ANTENNAS; DATA ACQUISITION; ELECTRONS; FLUCTUATIONS; HOT SPOTS; LIMITERS; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETIC SURFACES; PLASMA; PLASMA DENSITY; PLASMA SCRAPE-OFF LAYER; POWER DENSITY; TORE SUPRA TOKAMAK; WAVE PROPAGATION; BOUNDARY LAYERS; CLOSED PLASMA DEVICES; ELECTRICAL EQUIPMENT; ELEMENTARY PARTICLES; EQUIPMENT; FERMIONS; HEATING; HIGH-FREQUENCY HEATING; LAYERS; LEPTONS; MAGNETIC FIELD CONFIGURATIONS; NON-INDUCTIVE CURRENT DRIVE; PLASMA HEATING; SORPTION; THERMONUCLEAR DEVICES; TOKAMAK DEVICES; VARIATIONS

Citation Formats


                    Oosako, T, Ekedahl, A, Goniche, M, Achard, J, Decker, J, and Peysson, Y. Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore.  United States: N. p., 2011. 
        Web.  doi:10.1063/1.3664969.

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                    Oosako, T, Ekedahl, A, Goniche, M, Achard, J, Decker, J, & Peysson, Y. Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore.  United States.  https://doi.org/10.1063/1.3664969

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                    Oosako, T, Ekedahl, A, Goniche, M, Achard, J, Decker, J, and Peysson, Y. 2011.  
        "Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore".  United States.  https://doi.org/10.1063/1.3664969.

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@article{osti_21612484,

  title        = {Characterisation of SOL density fluctuations in front of the LHCD PAM launcher in Tore},

  author       = {Oosako, T and Ekedahl, A and Goniche, M and Achard, J and Decker, J and Peysson, Y},

  abstractNote = {The density fluctuations, modified by Lower Hybrid Wave (LHW), is analyzed in Tore Supra with reference to the injected LHW power, density and the gap between LCFS (Last Closed Flux Surface) and the PAM (passive-active-multijunction) launcher. The density fluctuations are measured with RF probes installed at the PAM launcher front. A density scan at nominal toroidal field (3.8 T) shows that the fluctuations rate stays nearly constant ({approx}50%) for <n{sub e}><3.5x10{sup 19}m{sup -3} and with LHW power up to 2MW. However, when increasing the density above <n{sub e}><{approx}4.2x10{sup 19}m{sup -3}, using strong gas puffing, the fluctuation rate increases to >70% and is characterized by strong negative spikes, with typical frequency >100kHz. These are most likely originating from acceleration of electrons in the LHW near field due to parasitic absorption, as evidenced on the IR images, showing hot spots on the side limiters.},

  doi          = {10.1063/1.3664969},

  url          = {https://www.osti.gov/biblio/21612484},
  journal      = {AIP Conference Proceedings},

  issn         = {0094-243X},

  number       = 1,

  volume       = 1406,

  place        = {United States},

  year         = {Fri Dec 23 00:00:00 EST 2011},

  month        = {Fri Dec 23 00:00:00 EST 2011}

}

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