Electron Bernstein wave heating and emission measurement through the very narrow O-X-B mode conversion window in the LHD

H. Igami, S. Kubo, T. Shimozuma, Y. Yoshimura, H. Takahashi, M. Nishiura, S. Ogasawara, R. Makino, Hiroshi Idei, K. Nagasaki, T. Seki, M. Osakabe, T. Mutoh

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    1 Citation (Scopus)

    Abstract

    In the large helical device (LHD), the theoretically predicted width of the ordinary-extraordinary-electron Bernstein wave (O-X-B) mode conversion (MC) window is comparable to the beam width and the power deposition is located in the off-axis region if the 77GHz fundamental electron cyclotron (EC) wave of is launched from an existing horizontal port antenna. In the experiment, the actual MC window location was looked for with changing the aiming. The effective aiming with that the increase of the stored energy was observed was two degrees apart from the location of the theoretical MC window at a maximum. Measurement of the waves originated from the thermally emitted EBW and radiated via the B-X-O mode conversion process is effective to improve the accuracy of the theoretical prediction with comparison between the theoretical and the experimental results. The theoretical prediction suggests that the width of the MC window of the fundamental 77GHz EC wave can be expanded if the lower port antenna is used. On the other hand, the MC window of the second harmonic 154GHz EC wave is blocked by horizontal port wall if another horizontal port antenna is used. It is required to move the final mirror of the quasi-optical antenna toward the plasma surface. Focusing of the beam at the plasma cutoff is (PC) also necessary for the effective mode conversion.

    Original languageEnglish
    Title of host publicationRadiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference
    PublisherAmerican Institute of Physics Inc.
    Pages490-493
    Number of pages4
    Volume1580
    ISBN (Print)9780735412101
    DOIs
    Publication statusPublished - Jan 1 2014
    Event20th Topical Conference on Radiofrequency Power in Plasmas - Sorrento, Italy
    Duration: Jun 25 2013Jun 28 2013

    Other

    Other20th Topical Conference on Radiofrequency Power in Plasmas
    CountryItaly
    CitySorrento
    Period6/25/136/28/13

    Fingerprint

    heating
    antennas
    electrons
    cyclotrons
    predictions
    cut-off
    mirrors
    harmonics
    energy

    All Science Journal Classification (ASJC) codes

    • Physics and Astronomy(all)

    Cite this

    Igami, H., Kubo, S., Shimozuma, T., Yoshimura, Y., Takahashi, H., Nishiura, M., ... Mutoh, T. (2014). Electron Bernstein wave heating and emission measurement through the very narrow O-X-B mode conversion window in the LHD. In Radiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference (Vol. 1580, pp. 490-493). American Institute of Physics Inc.. https://doi.org/10.1063/1.4864595

    Electron Bernstein wave heating and emission measurement through the very narrow O-X-B mode conversion window in the LHD. / Igami, H.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Takahashi, H.; Nishiura, M.; Ogasawara, S.; Makino, R.; Idei, Hiroshi; Nagasaki, K.; Seki, T.; Osakabe, M.; Mutoh, T.

    Radiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference. Vol. 1580 American Institute of Physics Inc., 2014. p. 490-493.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Igami, H, Kubo, S, Shimozuma, T, Yoshimura, Y, Takahashi, H, Nishiura, M, Ogasawara, S, Makino, R, Idei, H, Nagasaki, K, Seki, T, Osakabe, M & Mutoh, T 2014, Electron Bernstein wave heating and emission measurement through the very narrow O-X-B mode conversion window in the LHD. in Radiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference. vol. 1580, American Institute of Physics Inc., pp. 490-493, 20th Topical Conference on Radiofrequency Power in Plasmas, Sorrento, Italy, 6/25/13. https://doi.org/10.1063/1.4864595
    Igami H, Kubo S, Shimozuma T, Yoshimura Y, Takahashi H, Nishiura M et al. Electron Bernstein wave heating and emission measurement through the very narrow O-X-B mode conversion window in the LHD. In Radiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference. Vol. 1580. American Institute of Physics Inc. 2014. p. 490-493 https://doi.org/10.1063/1.4864595
    Igami, H. ; Kubo, S. ; Shimozuma, T. ; Yoshimura, Y. ; Takahashi, H. ; Nishiura, M. ; Ogasawara, S. ; Makino, R. ; Idei, Hiroshi ; Nagasaki, K. ; Seki, T. ; Osakabe, M. ; Mutoh, T. / Electron Bernstein wave heating and emission measurement through the very narrow O-X-B mode conversion window in the LHD. Radiofrequency Power in Plasmas - Proceedings of the 20th Topical Conference. Vol. 1580 American Institute of Physics Inc., 2014. pp. 490-493
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    abstract = "In the large helical device (LHD), the theoretically predicted width of the ordinary-extraordinary-electron Bernstein wave (O-X-B) mode conversion (MC) window is comparable to the beam width and the power deposition is located in the off-axis region if the 77GHz fundamental electron cyclotron (EC) wave of is launched from an existing horizontal port antenna. In the experiment, the actual MC window location was looked for with changing the aiming. The effective aiming with that the increase of the stored energy was observed was two degrees apart from the location of the theoretical MC window at a maximum. Measurement of the waves originated from the thermally emitted EBW and radiated via the B-X-O mode conversion process is effective to improve the accuracy of the theoretical prediction with comparison between the theoretical and the experimental results. The theoretical prediction suggests that the width of the MC window of the fundamental 77GHz EC wave can be expanded if the lower port antenna is used. On the other hand, the MC window of the second harmonic 154GHz EC wave is blocked by horizontal port wall if another horizontal port antenna is used. It is required to move the final mirror of the quasi-optical antenna toward the plasma surface. Focusing of the beam at the plasma cutoff is (PC) also necessary for the effective mode conversion.",
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    AU - Kubo, S.

    AU - Shimozuma, T.

    AU - Yoshimura, Y.

    AU - Takahashi, H.

    AU - Nishiura, M.

    AU - Ogasawara, S.

    AU - Makino, R.

    AU - Idei, Hiroshi

    AU - Nagasaki, K.

    AU - Seki, T.

    AU - Osakabe, M.

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