高周波数ジャイロトロンにおける周波数連続可変性と高性能化の研究

2013 Fiscal Year Annual Research Report

• Project/Area Number: 23760307
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: 池田 亮介 独立行政法人日本原子力研究開発機構, 核融合研究開発部門 那珂核融合研究所, 任期付研究員 (80533364)
• Keywords: ジャイロトロン / ジャイロBWO / 周波数連続可変 / 動的核偏極

Research Abstract

蛋白質構造解析にて用いられる600MHz核磁気共鳴分光の動的核偏極による高感度化光源として，394GHz近傍にて周波数可変幅2GHz以上，発振出力100W程度の周波数連続可変ジャイロトロンの実現を目指した．幅広い周波数連続可変を実現するには，設計発振モードの強磁場側で発振するモードとの競合を避けることが不可欠である．電子銃と空胴共振器間の距離，電子銃のカソード径に対して空胴共振器へ入射可能な電子ビーム径などを考慮し，最終的にTE7,3,qモード(q:軸方向モード次数)を選択した．発振性能の低下を抑えるには，空胴共振器へ入射する電子ビームの速度分散を低く抑えることが重要である．電子軌道計算コードEGUNを用いて電子銃形状の最適化設計を行い，磁力線に垂直方向の電子速度と平行方向の速度比が1.0～2.5の高い領域においても，その分散が5%以下となる設計を実現した．空胴共振器は空胴半径2mm，空胴長25mmとし，Q値（Q～11500）を高めることで発振開始電流を下げ，周波数連続可変性を生み出す高q次数の軸方向モードの励起を狙った．製作したジャイロトロンは15T超伝導マグネットにセットし，実験はビーム加速電圧15kV，電子ビーム電流0.4A条件で行った．共振器の磁場強度掃引試験では，10次までの軸方向モードが励起することで14.25Tから14.8Tまで連続発振し，発振周波数は393.5GHzから397.4GHzまでの幅広い周波数連続可変を実現した．発振出力は50W以上が得られ，最高では170Wに達した．また，電子銃のカソードとアノード間の電圧を変化させ電子の平行速度を変化させることでも0.9GHzの周波数連続可変を得ることに成功した．本研究で達成した3.9GHzに亘る周波数可変幅は，過去に報告された400GHz帯のジャイロトロンやジャイロBWOにおける結果を大きく上回る成果である．

Research Products

• [Journal Article] Broadband Continuously Frequency Tunable Gyrotron for 600MHz DNP-NMR Spectroscopy (2014)
  • Author(s): Ryosuke IKEDA, Yuusuke YAMAGUCHI, Yoshinori TATEMATSU, Toshitaka IDEHARA, Isamu OGAWA, TeruoSAITO, Yoh MATSUKI and Toshimichi FUJIWARA
  • Journal Title: Plasma and Fusion Research Volume: 9 Pages: 1206058-1, -3
  • DOI: 10.1585/pfr.9.1206058
  • Peer Reviewed
• [Journal Article] 460 GHz second harmonic gyrotrons for a 700 MHz DNP-NMR spectroscopy (2013)
  • Author(s): T. Idehara, Y. Tatematsu, Y. Yamaguchi, R. Ikeda, I. Ogawa, T. Saito, Y. Matsuki, K. Ueda, T. Fujiwara and M. Toda
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Mo1-4
  • DOI: 10.1109/IRMMW-THz.2013.6665482
• [Journal Article] Progress Of High Power Long Pulse Gyrotron For Fusion Application (2013)
  • Author(s): Keishi Sakamoto, Ken Kajiwara, Yasuhisa Oda, Kazuo Hayashi, Ryosuke Ikeda, Koji Takahashi, Takayuki Kobayashi and Shinichi Moriyama
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Mo5-1
  • DOI: 10.1109/IRMMW-THz.2013.6665527
• [Journal Article] Experiment For Over 200 kW Oscillation Of A 295 GHz Pulse Gyrotron (2013)
  • Author(s): Teruo Saito, Yuusuke Yamaguchi, Shinji Ikeuchi, Yoshinori Tatematsu, Ryosuke Ikeda, Isamu Ogawa, Toshitaka Idehara, Shin Kubo, Takashi Shimozuma, Masaki Nishiura, Kenji Tanaka and Jun Kasa
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Mo5-3
  • DOI: 10.1109/IRMMW-THz.2013.6665528
• [Journal Article] Experimental Verification Of A Self-Consistent Calculation For Continuous Frequency-Tune With A 400 GHz Band Second Harmonic Gyro-BWO (2013)
  • Author(s): Yuusuke Yamaguchi, Yoshinori Tatematsu, Teruo Saito, Taiki Kuwahaha, Ryosuke Ikeda, Isamu Ogawa, Toshitaka Idehara and Olgierd Dumbrajs
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Mo P1-53
  • DOI: 10.1109/IRMMW-THz.2013.6665445
• [Journal Article] Application Of A Potential Profile For Controlling The Beam Laminarity in A Magnetron Injection Gun (2013)
  • Author(s): Yuusuke Yamaguchi, Yoshinori Tatematsu, Teruo Saito, Ryosuke Ikeda, Isamu Ogawa and Toshitaka Idehara
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Mo P1-54
  • DOI: 10.1109/IRMMW-THz.2013.6665446
• [Journal Article] Long Pulse Operation Of A Dual Frequency Gyrotron For JT-60SA (2013)
  • Author(s): Takayuki Kobayashi, Masayuki Sawahata, Masayuki Terakado, Shinichi Hiranai, Kenji Wada, Yoshikatsu Sato, Jun Hinata, Kenji Yokokura, Katsumichi Hoshino, Ken Kajiwara, Yasuhisa Oda, Koji Takahashi, Ryosuke Ikeda, Shinichi Moriyama and Keishi Sakamoto
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Tu1-3
  • DOI: 10.1109/IRMMW-THz.2013.6665554
• [Journal Article] Power Improvement On Gyrotron FU CW GIII (2013)
  • Author(s): Yoshinori Tatematsu, Tatsuru Kawase, Ryoichi Ichioka, Yuusuke Yamaguchi, Isamu Ogawa, Ryosuke Ikeda, Toshitaka Idehara and Teruo Saito
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: Tu1-5
  • DOI: 10.1109/IRMMW-THz.2013.6665556
• [Journal Article] Development Of Broadband Frequency Tunable Gyrotron Operating At The Fundamental Resonance For 600 MHz DNP-NMR Spectroscopy (2013)
  • Author(s): Ryosuke Ikeda, Toshitaka Idehara, Yoshinori Tatematsu, Isamu Ogawa, Yuusuke Yamaguchi, Tomohiro Kanemaki and Teruo Saito
  • Journal Title: Proceedings of the 38th International Conference on Infrared, Millimeter, and Terahertz Waves Volume: 2013 Pages: We P2-80
  • DOI: 10.1109/IRMMW-THz.2013.6665701
• [Journal Article] Progress of development for 170GHz gyrotron and 5kHz modulation power supply for ITER (2013)
  • Author(s): Ken Kajiwara, Yasuhisa Oda, Ryosuke Ikeda, Koji Takahashi and Keishi Sakamoto
  • Journal Title: AIP Conference Proceedings Volume: 1580 Pages: p.554-557
  • DOI: 10.1063/1.4864611
• [Presentation] Progress on Development of Mega-Watt Multi-Frequency Gyrotron in JAEA (2014)
  • Author(s): Ryosuke Ikeda, Ken Kajiwara, Yasuhisa Oda, Koji Takahashi, Takayuki Kobayashi, Shinichi Moriyama and Keishi Sakamoto
  • Organizer: The 5th International Workshop on Far-Infrared Technologies 2014
  • Place of Presentation: University of Fukui, Japan
  • Year and Date: 20140305-20140307
• [Presentation] Development of 170 GHz / 1MW Gyrotron system for ITER in JAEA (2014)
  • Author(s): R. Ikeda, K. Kajiwara, Y. Oda, K. Takahashi, T. Kobayashi, S. Moriyama and K. Sakamoto
  • Organizer: Japan-Korea Workshop on Physics and Technology of Heating and Current Drive
  • Place of Presentation: Awara, Japan
  • Year and Date: 20140120-20140122
• [Presentation] ITER 電子サイクロトロン波加熱・電流駆動用 170 GHz / 1MWジャイロトロン開発の進展 (2013)
  • Author(s): 池田 亮介，梶原 健，小田 靖久，高橋 幸司，青木 貴志， 大島 克己，坪田 直明，小林 貴之，森山 伸一，坂本 慶司
  • Organizer: プラズマ・核融合学会 第30回年会
  • Place of Presentation: 東京工業大学
  • Year and Date: 20131203-20131206
• [Presentation] Development Of Broadband Frequency Tunable Gyrotron Operating At The Fundamental Resonance For 600 MHz DNP-NMR Spectroscopy (2013)
  • Author(s): Ryosuke Ikeda, Toshitaka Idehara, Yoshinori Tatematsu, Isamu Ogawa, Yuusuke Yamaguchi, Tomohiro Kanemaki and Teruo Saito
  • Organizer: The 38th International Conference on Infrared, Millimeter, and Terahertz Waves
  • Place of Presentation: Maintz, Germany
  • Year and Date: 20130901-20130906