Realization of an intense, sub-terahertz radiation source to produce high quality output by simultaneously stabilizing the intensity and the frequency of the gyrotron output beam.

• Project/Area Number: 15K05362
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Plasma science
• Research Institution: University of Fukui
• Principal Investigator: Ogawa Isamu 福井大学, 遠赤外領域開発研究センター, 教授 (90214014)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2017: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2015: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: ジャイロトロンの出力・周波数の同時安定化 / ミリ波・サブミリ波帯の強力な光源 / 周波数のフィードバック制御 / 出力電磁波強度のフィードバック制御 / サブミリ波帯高出力光源 / 周波数の安定化 / 出力・周波数の安定化

Outline of Final Research Achievements

Simultaneous stabilization of the intensity and the frequency of the gyrotron output beam is carried out. Frequency fluctuation level of CW, 190 GHz gyrotron output was 10 MHz. Frequency fluctuation level was decreased to 2 MHz by reducing fluctuation level of cooling water temperature of gyrotron cavity region down to 0.1℃. Frequency was stabilized within 0.5 MHz for 1 hour by the feedback control to adjust body potential.
The linearly polarized output beam from gyrotron is incident on polarizer. The intensity of penetrating beam is changed by rotating the polarizer. The intensity of penetrating beam was stabilized within 1 % for 1 hour by the feedback control to adjust rotating angle of the polarizer. Simultaneous stabilizations of the intensity and the frequency of the gyrotron output beam are carried out by the feedback controls.

Research Products

• [Journal Article] High purity mode CW gyrotron covering the sub-THz to THz range using a 20 T super-conducting magnet (2017)
  • Author(s): Toshitaka Idehara, Isamu Ogawa, Dietmar Wagner, Manfred Thumm, Kosuke Kosuga, and Svilen Petrov Sabchevski
  • Journal Title: GENERIC COLORIZED JOURNAL Volume: 印刷中
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Modulation and Stabilization of the Output Power and Frequency of FU Series Gyrotrons (2016)
  • Author(s): T.Idehara, E.M.Khutoryan, I.Ogawa, Y.Matsuki and T.Fujiwara
  • Journal Title: Teraherrtz Science and Technology Volume: 9 Pages: 117-129
  • Peer Reviewed / Int'l Joint Research / Acknowledgement Compliant
• [Journal Article] Further Characterization of 394-GHz Gyrotron FU CW GII with Additional PID Control System for 600-MHz DNP-SSNMR Spectroscopy (2016)
  • Author(s): Keisuke Ueda, Yoh Matsuki, Toshimichi Fujiwara, Yoshinori Tatematsu, Isamu Ogawa, Toshitaka Idehara
  • Journal Title: J Infrared Milli Terahz Waves Volume: 印刷中 Issue: 9 Pages: 1-12
  • DOI: 10.1007/s10762-016-0276-7
  • Peer Reviewed / Open Access
• [Journal Article] First millimeter-wave spectroscopy of ground-state positronium (2015)
  • Author(s): A.Miyazaki, T.Yamazaki, T.Suehara, T.Namba, S.Asai, T.Kobayashi, H.Saito, Y.Tatematsu, I.Ogawa, T.Idehara
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 2015 Issue: 1 Pages: 11C01-0
  • DOI: 10.1093/ptep/ptu181
  • Peer Reviewed / Open Access
• [Presentation] サブテラヘルツジャイロトロンの 電磁波ビーム強度と周波数の同時安定化 (2018)
  • Author(s): 小川 勇，出原敏孝
  • Organizer: 日本物理学会 第73回年次大会