Linear and Non-Linear Inserts for Genuinely Wideband Continuous Frequency Tunable Coaxial Gyrotron Cavities

  • Zisis C. Ioannidis
  • Olgierd Dumbrajs
  • Ioannis G. Tigelis


We consider two continuous frequency tunable CW coaxial gyrotron oscillators, one 330 GHz with 3 GHz bandwidth and output power 50 – 400 W for scientific applications and one 30 GHz with 0.4 GHz bandwidth and output power 40 – 140 kW for industrial applications. The continuous tuning of both gyrotrons is achieved by moving the linearly tapered inner conductor in the axial direction in combination with the proper adjustment of the operating magnetic field. We consider also a non-linear tapering, which makes it possible to reduce the length of the insert and to improve efficiency of the device.


Coaxial resonators Gyrotrons Frequency tuning 



The authors would like to thank the anonymous reviewers for their valuable comments, which improve significantly the content of this work.


  1. 1.
    O. Dumbrajs, J. A. Heikkinen, and H. Zohm, “Electron cyclotron heating and current drive control by means of frequency step-tunable gyrotrons, ” Nucl. Fus. 41, 927–944 (2001).CrossRefADSGoogle Scholar
  2. 2.
    H. Zohm and M. Thumm, “On the use of step-tunable gyrotrons in ITER,” J. Phys. Conference Series 25, 274–282 (2005).CrossRefADSGoogle Scholar
  3. 3.
    L. R. Becerra et al., “Dynamic nuclear polarization with a cyclotron-resonance maser at 5 T,” Phys. Rev. Lett. 71, 3561–3564 (1993).CrossRefADSGoogle Scholar
  4. 4.
    V. Bajaj et al., “Dynamic nuclear polarization at 9T using a novel 250 GHz gyrotron microwave source,” J. Magn. Reson. 160, 85–90 (2003).CrossRefADSGoogle Scholar
  5. 5.
    S. Mitsudo et al., “High power, frequency tunable, submillimeter wave ESR device using a gyrotron as a radiation source,” Int. J. Infrared Millim. Waves 21, 661–676 (2000).CrossRefGoogle Scholar
  6. 6.
    G. Link et al., “Sintering of advanced ceramics using a 30 GHz, 10 kW, CW industrial gyrotron,” IEEE Trans. Plasma Sci. 27, 547–554 (1999).CrossRefADSGoogle Scholar
  7. 7.
    J. R. Sirigiri, M. A. Shapiro and R. J. Temkin, Wideband Continuous Frequency Tunable 330 GHz Gyrotron Oscillator, Joint 29th Int. Conf. on Infrared and Millimeter Waves and 12th Int. Conf. on Terahertz Electronics, 2004, pp. 621–622.Google Scholar
  8. 8.
    S. Sabchevski, T. Idehara, S. Misudo, and T. Fujiwara, “Conceptual design study of a novel gyrotron for NMR/DNP spectroscopy,” Int. J. Infrared Millim. Waves 26, 1241–1264 (2005).CrossRefGoogle Scholar
  9. 9.
    I. I. Antakov, E. V. Zasypkin, and E. V. Sokolov, “Electron tuning of frequency in gyrotrons,” Int. J. Infrared Millim. Waves 14, 1001–1015 (1993).CrossRefADSGoogle Scholar
  10. 10.
    O. Dumbrajs, A. Möbius, and M. Muehleisen, Ein in der Frequenzeinstellbares Gyrotron, Patentanmeldung 19532785, Anmeldetag: 06.09.95. Deutsches Patentamt, Muenchen, 17. April 1997, (1997).Google Scholar
  11. 11.
    O. Dumbrajs and A. Möbius, “Tunable coaxial gyrotron for plasma heating and diagnostics,” Int. J. Electron. 84, 411–419 (1998).CrossRefGoogle Scholar
  12. 12.
    V. Zapevalov, private communication.Google Scholar
  13. 13.
    M. Yu. Glyavin, A. G. Luchinin, M. V. Morozkin, and V. I. Khizhnyak, “Continuous wideband frequency tuning of a gyrotron,” Radiophys. Quantum Electron. (in print).Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Zisis C. Ioannidis
    • 1
  • Olgierd Dumbrajs
    • 2
    • 3
  • Ioannis G. Tigelis
    • 1
  1. 1.Department of Electronics, Computing, Telecommunications and Control, Faculty of PhysicsNational and Kapoditrian University of AthensAthensGreece
  2. 2.Department of Engineering, Physics and MathematicsHelsinki University of Technology, Euratom-TEKES AssociationHelsinkiFinland
  3. 3.Institute of Solid State PhysicsUniversity of LatviaRigaLatvia

Personalised recommendations