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Fuks M. I., Schamiloglu E. ., Kovalev N. F. Relativistic magnetrons’ development stages. Izvestiya VUZ. Applied Nonlinear Dynamics, 2016, vol. 24, iss. 6, pp. 39-53. DOI: 10.18500/0869-6632-2016-24-6-39-53

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Relativistic magnetrons’ development stages

Fuks Mihail Isaakovich, Department of Electrical & Computer Engineering, University of New Mexico
Schamiloglu Edl , Department of Electrical & Computer Engineering, University of New Mexico
Kovalev Nikolaj Fedorovich, Institute of Applied Physics of the Russian Academy of Sciences

A paper presents the main stages of relativistic magnetrons’ development. We describe the designs eliminating conventional magnetrons’ shortcomings and restrictions which are associated with a radial output of radiation through a narrow slot in one of the magnetron resonators. A low breakdown threshold and an operation in only nondegenerate modes are among these restrictions. In the paper we consider the design of the magnetron with a diffraction output of radiation, where all magnetron’s resonators are extended into conical antenna to the cross-section where the cutoff frequency is lower than the frequency of generation. This magnetron with axial symmetrical output of radiation can operate in any mode and a switch to the degenerate oscillation does not lead to a catastrophe which may occur in conventional magnetrons. We managed to increase an efficiency of the magnetron by optimizing its diffraction output with a depth of resonators increasing in the antenna. In the first experiment the electron efficiency of the magnetron achieved the value exceeding 60%. The replacement of a solid cathode to the cathode transparent to azimuthal electric field of synchronous wave, allowed us to shorten the leading edge of radiated wave to the duration of leading edge of accelerating voltage. Transparent cathode consists of separate emitters oriented along the axis and periodically placed at the circle with a radius of the cathode. High efficiency was also achieved in the magnetron with a long virtual cathode, the use of which allowed us to eliminate both plasma responsible for a pulse shortening and an electron bombardment reducing a cathode’s lifespan. We showed a possibility to transform the operating π-mode into the output radiation with a simplified structure including the radiation with the structure similar to Gaussian. This can be achieved in a compact design of the magnetron. In a regime of fast mode switching induced by external signal, we estimated the influence of noise leading to the blurring of the boundary magnetic fields intrinsic to different modes. In magnetic fields within these broaden boundaries the generation of neighboring magnetron operating modes becomes unpredictable. Alternate regions of magnetic fields with stable and unstable regimes of generation are observed on the map of generation regimes of the magnetron, which makes it difficult to switch the operating modes by small external signal.  

  1. Bekefi G., Orzechowski J.J. Giant microwave burst beam magnetron // Phys. Rev. Lett. 1976. Vol. 37, Issue 6. P. 379–382.
  2. Kovalev N.F., Kol’chugin B.D., Nechaev V.T., Ofitserov M.M., Soluyanov E.I., Fuks M.I. Relativistic magnetron with diffraction output // Tech. Phys. Let. 1977. Issue 3. P. 430–431.
  3. Kovalev N.F., Krastelev E.G., Kuznetsov M.I., Maine A.M., Ofitserov M.M., Papadichev V.A., Fuks M.I., Chekanova L.N. High power relativistic 3-см magnetron // Tech. Phys. Let. 1980. Issue 6. P. 197–198.,
  4. Vlasov S.N., Zhislin G.M., Orlova I.M., Petelin M.I., Rogacheva G.G. Opened resonators as waveguides with varying cross sections // Radiophysics and Quantum Electronics. 1969. Vol. 12, Issue 8. P. 1236–1244,
  5. Goplen B., Ludeking L., Smithe D., Warren G. User-configurable MAGIC for electromagnetic PIC calculations // Comput. Phys. Commun. 1995. Vol. 87, Issue 1. P. 54–86.
  6. Daimon M., Jiang W. Modified configuration of relativistic magnetron with diffraction output for efficiency improvement // Appl. Phys. Lett. 2007. Vol. 91, Issue 19. P. 191503–191505.
  7. Fuks M.I., Schamiloglu E. Rapid start of oscillations in a magnetron with a «transparent» cathode // Phys. Rev. Lett. 2005. Vol. 95. 205101-1-4.
  8. Fuks M.I., Schamiloglu E. 70% efficient relativistic magnetron with axial extraction of radiation through a horn antenna // IEEE Trans. Plasma Sci. 2010. Vol. 38, Issue 6. P. 1302–1312.
  9. Leach C., Prasad S., Fuks M., Schamiloglu E. Suppression of leakage current in a relativistic magnetron using a novel cathode endcap design // IEEE Trans. Plasma Sci. 2011. Vol. 40, Issue 8. P. 819–822.
  10. Bogdankevich L.S., Rukhadze A.A. Stability REB and a problem of critical currents // Achievements of Physical Sciences. 1971. Vol. 103. P. 609–613.
  11. Breizman B.N., Rutov D.D. // Nuclear Physics. 1974. Vol. 14. P. 873–907 (in Russian).
  12. Pikovsky A., Rosenblum M., Kurths J. Synchronization: A Universal Concept in Nonlinear Sciences. Cambridge University Press, 2003.
  13. Bugaev S.P., Kim A.A., Koshelev V.I. Plasma motion and vacuum breakdown in coaxial diodes with magnetic insulation // Emission High Current Electronics. Novosibirsk: Science, 1984.
  14. Fuks M., Prasad S., Schamiloglu E. Efficient magnetron with virtual cathode // IEEE Trans. Plasma Sci. 2016. Vol. 44(1), Issue 8. P. 1298–1302.
  15. Fuks M.I., Kovalev N.F., Andreev A.D., Schamiloglu E. Mode conversion in a magnetron with axial extraction of radiation // IEEE Trans. Plasma Sci. 2006. Vol. 34, Issue 3. P. 620–626.
  16. Prasad S., Leach C., Fuks M.I., Schamiloglu E. Compact relativistic magnetron with Gaussian radiation pattern // IEEE Trans. Plasma Sci. 2012. Vol. 40, Issue 11. P. 3116–3120.
  17. Liu M., Michel C., Prasad S., Fuks M.I., Schamiloglu E., Liu C.-L. RF mode switching in a relativistic magnetron with diffraction output // Appl. Phys. Lett. 2010. Vol. 97, Issue 1. P. 251501-11-3.
  18. Liu M., Liu C.-L., Galbreath D., Michel C., Prasad S., Fuks M.I., Schamiloglu E. Frequency switching in a relativistic magnetron with diffraction output // J. Appl. Phys. 2011. Vol. 110, Issue 3. P. 039303-1-7.
  19. Liu M., Fuks M.I., Schamiloglu E., Liu C.-L. Mode switching in a 12-cavity relativistic magnetron with axial extraction of radiation // IEEE Trans. Plasma Sci. 2012. Vol. 40, Issue 6. P. 1569–1574.
  20. Yamamoto K., Kuranuma H., Koinuma T., Tashiro T. A study of magnetron noise // IEEE Trans. Electron Dev. 1987. Vol. ED-34, Issue 5. P. 1223–1226.
  21. Tahir I., Dexter A., Carter R. Noise performance of frequency- and pulse-locked CW magnetrons operated as current-controlled oscillators // IEEE Trans. Electron Devices. 2005. Vol. 52, Issue 9. P. 2096–2103.
  22. Neculae V.B., Gilgenbach R.M., Lau Y.Y. Low-noise microwave magnetrons by azimuthally varying axial magnetic field // Appl. Phys. Lett. 2003. Issue 83. P. 1938–1940.
  23. Nechaev V.E., Petelin M.I., Fuks M.I. Perspectives of relativistic electron beams in devices of magnetron types // Tech. Phys Lett. 1977. Vol. 3, Issue 15. P. 763–767.
  24. Fuks M.I., Nechaev V.E. Theoretical and experimental study of relativistic magnetrons // IEEE/MTT-s Int. Microwave Symp. Digest. Orlando. 1979. P. 79–84.
  25. Andreev A.D., Hendricks K.J., Fuks M.I., Schamiloglu E. Analytic calculation of anode current in relativistic magnetron // Pulse Power Conference. 2009. P. 502–506.
  26. Andreev A.D., Hendricks K.J., Fuks M.I., Schamiloglu E. Elementary theory of a relativistic magnetron operation: Dispersion diagram // J. Directed Energy. 2013. Vol. 5, Issue 1. P. 1–41.
  27. Liu M., Liu C.-L., Fuks M.I., Schamiloglu E. Hysteresis dependence of mode separation on time-varying applied voltage in a relativistic magnetron with diffraction output // IEEE Trans. Plasma Sci. 2012. Vol. 40, Issue 6. P. 1569–1574.
  28. Fuks M.I., Schamiloglu E., Prasad S., Galbreath D. Mode separation in a magnetron with diffraction output driven by a transparent cathode. IVEC, 2010.
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