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Parasitic Oscillations in Smooth-Wall Circular Symmetric Gyrotron Beam Ducts

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Abstract

In order to study parasitic oscillation that may occur in a realistic beam duct upstream to the gyrotron cavity, the self-consistent linear and spectral code TWANGlinspec has been modified. The large inhomogeneities in the smooth-wall beam duct geometry or in the magnetic field profile required the implementation of a numerical approach using a hybrid finite element method. The new model permits to characterize a large number of potentially spurious TE modes. Compared to previous studies on gyrotron beam duct instabilities, an extended interaction space including also the gyrotron cavity has been considered. The role of the connecting part between the beam duct and the cavity, called spacer, is highlighted and it is shown that the gyro backward-wave TE modes excited in this region generally have their minimum starting current. The sensitivity of the minimum starting current on electron beam velocity spread is also evaluated.

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References

  1. I. I. Antakov, I. G. Gachev, and E. V. Zasypkin. Self-excitation of spurious oscillations in the drift region of gyrotrons and their influence on gyrotron operation. IEEE Transactions on Plasma Science, 22(5):878–882, October 1994.

  2. K Sakamoto, A Kasugai, Y Ikeda, K Hayashi, K Takahashi, S Moriyama, M Seki, T Kariya, Y Mitsunaka, T Fujii, and T Imai. Development of 170 and 110 GHz gyrotrons for fusion devices. Nuclear Fusion, 43(8):729–737, August 2003.

  3. M. Pedrozzi, S. Alberti, J. P. Hogge, M. Q. Tran, and T. M. Tran. Electron beam instabilities in gyrotron beam tunnels. Physics of Plasmas, 5(6):2421–2430, June 1998.

  4. G. Gantenbein, G. Dammertz, J. Flamm, S. Illy, S. Kern, G. Latsas, B. Piosczyk, T. Rzesnicki, A. Samartsev, A. Schlaich, M. Thumm, and I. Tigelis. Experimental Investigations and Analysis of Parasitic RF Oscillations in High-Power Gyrotrons. IEEE Transactions on Plasma Science, 38(6):1168–1177, June 2010.

  5. G. G. Denisov, V. E. Zapevalov, A. G. Litvak, and V. E. Myasnikov. Megawatt Gyrotrons for ECR Heating and Current-Drive Systems in Controlled-Fusion Facilities. Radiophysics and Quantum Electronics, 46(10):757–768, October 2003.

  6. M. Blank, K. Felch, P. Borchard, P. Cahalan, S. R. Cauffman, Tak Sum Chu, and H. Jory. Demonstration of a high-power long-pulse 140-GHz gyrotron oscillator. IEEE Transactions on Plasma Science, 32(3):867–876, June 2004.

  7. I. G. Chelis, K. A. Avramidis, Z. C. Ioannidis, and I. G. Tigelis. Improved Suppression of Parasitic Oscillations in Gyrotron Beam Tunnels by Proper Selection of the Lossy Ceramic Material. IEEE Transactions on Electron Devices, 65(6):2301–2307, June 2018.

  8. M. Garven, J. P. Calame, B. G. Danly, K. T. Nguyen, B. Levush, F. N. Wood, and D. E. Pershing. A gyrotron-traveling-wave tube amplifier experiment with a ceramic loaded interaction region. IEEE Transactions on Plasma Science, 30(3):885–893, June 2002.

  9. I. G. Tigelis, J. L. Vomvoridis, and S. Tzima. High-frequency electromagnetic modes in a dielectric-ring loaded beam tunnel. IEEE Transactions on Plasma Science, 26(3):922–930, June 1998.

  10. Kwo Ray Chu, Han-Ying Chen, Chien-Lung Hung, Tsun-Hsu Chang, L.R. Barnett, Shih-Hung Chen, Tz-Te Yang, and D.J. Dialetis. Theory and experiment of ultrahigh-gain gyrotron traveling wave amplifier. IEEE Transactions on Plasma Science, 27(2):391–404, April 1999.

  11. K. R. Chu, L. R. Barnett, H. Y. Chen, S. H. Chen, Ch. Wang, Y. S. Yeh, Y. C. Tsai, T. T. Yang, and T. Y. Dawn. Stabilization of Absolute Instabilities in the Gyrotron Traveling Wave Amplifier. Physical Review Letters, 74(7):1103–1106, February 1995.

  12. Jiao Yu, Thomas M. Antonsen, and Gregory S. Nusinovich. Excitation of Backward Waves in Beam Tunnels of High-Power Gyrotrons. IEEE Transactions on Plasma Science, 38(6):1193–1199, June 2010.

  13. Chao-Hai Du and Pu-Kun Liu. Millimeter-Wave Gyrotron Traveling-Wave Tube Amplifiers. Springer Berlin Heidelberg, Berlin, Heidelberg, 2014.

  14. S. Alberti, F. Braunmueller, J. Genoud, J. P. Hogge, T. M. Tran, M. Q. Tran, K. Avramidis, I. G. Pagonakis, J. Jin, S. Illy, G. Gantenbein, J. Jelonnek, and F. Cismondi. Dual-frequency, 126/84 GHz, 1 MW gyrotron for the upgrade of the TCV EC-system. In 2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), pages 1–2, August 2015.

  15. S. Coda et al. Overview of the TCV tokamak program: scientific progress and facility upgrades. Nuclear Fusion, 57(10):102011, October 2017.

  16. S. Alberti, T. M. Tran, K. A. Avramides, F. Li, and J.-P. Hogge. Gyrotron parasitic-effects studies using the time-dependent self-consistent monomode code TWANG. 2011 36th International Conference on Infrared, Millimeter, and Terahertz Waves (irmmw-Thz), 2011.

  17. J. Genoud, T. M. Tran, S. Alberti, F. Braunmueller, J.-Ph Hogge, M. Q. Tran, W. C. Guss, and R. J. Temkin. Novel linear analysis for a gyrotron oscillator based on a spectral approach. Physics of Plasmas (1994-present), 23(4):043101, April 2016.

  18. F. Braunmueller, T. M. Tran, Q. Vuillemin, S. Alberti, J. Genoud, J.-Ph Hogge, and M. Q. Tran. TWANG-PIC, a novel gyro-averaged one-dimensional particle-in-cell code for interpretation of gyrotron experiments. Physics of Plasmas (1994-present), 22(6):063115, June 2015.

  19. F. Braunmueller, T. M. Tran, S. Alberti, J.-Ph Hogge, and M. Q. Tran. Moment-based, self-consistent linear analysis of gyrotron oscillators. Physics of Plasmas, 21(4):043105, April 2014.

  20. D.C. Sorensen, R.B. Lehoucq, C. Yang, and K. Maschhoff. ARPACK - Arnoldi Package, 1996.

  21. Franco Brezzi and Michel Fortin, editors. Mixed and Hybrid Finite Element Methods, volume 15 of Springer Series in Computational Mathematics. Springer New York, New York, NY, 1991.

  22. William H. Press, Brian P. Flannery, Saul A. Teukolsky, and William T. Vetterling. Numerical Recipes: The art of scientific computing. Cambridge Univ. Press, 1986.

  23. Germund Dahlquist and ke Björck. Numerical Methods. Courier Corporation, 2003.

  24. S. Alberti, T. M. Tran, S. Brunner, F. Braunmueller, J. Genoud, J.-Ph Hogge, and M. Q. Tran. Generalized Radiation Boundary Conditions in Gyrotron Oscillator Modeling. Journal of Infrared, Millimeter, and Terahertz Waves, pages 1–16, September 2015.

  25. D. Wagner, M. Thumm, G. Gantenbein, W. Kasparek, and T. Idehara. Analysis of a Complete Gyrotron Oscillator Using the Scattering Matrix Description. International Journal of Infrared and Millimeter Waves, 19(2):185–194, February 1998.

  26. K. A. Avramides, I. Gr Pagonakis, C. T. Iatrou, and J. L. Vomvoridis. EURIDICE: A code-package for gyrotron interaction simulations and cavity design. In E. Westerhof and Pwjm Nuij, editors, Ec-17 - 17th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating, volume 32, page 04016. E D P Sciences, Cedex A, 2012.

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Acknowledgements

We dedicate this article to our late friend T.M. Tran. This work was supported in part by the Swiss National Science Foundation, by the EUROfusion WP-HCD programme and by Fusion for Energy under Grants F4E-GRT-432 and F4E-GRT-553 to the European Gyrotron Consortium (EGYC). EGYC is a collaboration among SPC, Switzerland; KIT, Germany; HELLAS, Greece; IFP-CNR, Italy. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein are the sole responsibility of the authors and do not necessarily reflect the views of the European Commission and F4E. The author would like to thank D. Wagner and S. Brunner for precious scientific discussions.

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Authors and Affiliations

  1. Ecole Polytechnique Fédérale de Lausanne (EPFL), Swiss Plasma Center (SPC), CH-1015, Lausanne, Switzerland

    J. Genoud, S. Alberti, T. M. Tran, G. Le Bars, P. Kaminski, J.-Ph. Hogge & M. Q. Tran

  2. Institute for Pulsed Power and Microwave Technology, Karlsruhe Institue of Technology, 76131, Karlsruhe, Germany

    K. A. Avramidis

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  1. J. Genoud
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  2. S. Alberti
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  3. T. M. Tran
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  4. G. Le Bars
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  5. P. Kaminski
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  6. J.-Ph. Hogge
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  7. K. A. Avramidis
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  8. M. Q. Tran
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Correspondence to J. Genoud.

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T.M. Tran died before publication of this work was completed.

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Genoud, J., Alberti, S., Tran, T.M. et al. Parasitic Oscillations in Smooth-Wall Circular Symmetric Gyrotron Beam Ducts. J Infrared Milli Terahz Waves 40, 131–149 (2019). https://doi.org/10.1007/s10762-018-0548-5

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