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Magnetic Field Sensitivity in Depressed Collector for a Millimeter-Wave Gyrotron

  • Vishal Kesari
  • R. Seshadri
Conference paper
Part of the Lecture Notes in Electrical Engineering book series (LNEE, volume 524)

Abstract

The electron beam trajectories were simulated in a single-stage depressed collector for a millimeter-wave gyrotron. This collector was designed to handle the spent beam obtained after beam-wave interaction in the 100 kW gyrotron (accelerating voltage 55 kV and beam current 5 A). Similar to other high-power gyrotrons, this collector has larger volume considered at ground potential. The cathode and the beam-wave interaction cavity were considered at −40 kV and +15 kV, respectively. The collector sees the depression of 15 kV. The geometry of the collector is considered as three sections: (i) the open entrance conical section, (ii) the smooth cylindrical section, and (iii) the closed conical section. In order to simulate the beam trajectory from nonlinear taper to collector, the electron trajectories and spent beam power distribution data obtained from large-signal analysis have been fed at the entrance of mode converter of the gyrotron with required potentials applied. The collector geometry and the magnetic field are profiled to ensure the landing of the gyrating electrons to the wider smooth cylindrical section for better thermal management. The sensitivity of the magnetic field profile is studied and observed that for ±5% variation in the magnetic field profile would not shift the electron beam landing to conical sections, and the spent electron beam has no interception. The power dissipation on the collector is found to be 80.55 kW. The collector efficiency is calculated as ~48% for 120 kW RF output. The maximum thermal loading on collector inner surface is estimated as 0.38 kW/cm2.

Keywords

Depressed collector Electron trajectory simulation Millimeter-wave gyrotron W-band gyrotron 

References

  1. 1.
    Gilmour, A. S. (2011). Klystrons, traveling wave tubes, magnetrons, crossed-field amplifiers, and gyrotrons. Boston, London: Artech House.Google Scholar
  2. 2.
    Thumm, M. (2017). State-of-the-art of high power gyro- devices and free electron masers, Update 2016. Karlsruhe, Germany: KIT.Google Scholar
  3. 3.
    Nusinovich, G. S. (2004). Introduction to the Physics of Gyrotron. Maryland, USA: JHU.Google Scholar
  4. 4.
    Edgecombe, C. J. (1993). Gyrotron Oscillators: Their principles and practice. London: Taylor & Francis Ltd.Google Scholar
  5. 5.
    Kesari, V., & Basu, B. N. (2018). High power microwave tubes: Basics and trends. California for IOP Concise Physics, London: Morgan and Claypool Publishers.Google Scholar
  6. 6.
    Sakamoto, K., Tsuneoka, M., Kasugai, A., Takahashi, K., Maebava, S., Imai, T., et al. (1994). Major improvement of gyrotron efficiency with beam energy recovery. Physical Review Letters, 73(26), 3532–3535.CrossRefGoogle Scholar
  7. 7.
    Ling, G., Piosczyk, B., & Thumm, M. K. (2000). A new approach for a multistage depressed collector for gyrotrons. IEEE Transactions on Plasma Science, 28(3), 606–613.CrossRefGoogle Scholar
  8. 8.
    Piosczyk, B., Iatrou, C. T., Dammertz, G., & Thumm, M. (1996). Single-stage depressed collectors for gyrotrons. IEEE Transactions on Plasma Science, 24, 579–585.CrossRefGoogle Scholar
  9. 9.
    Piosczyk, B., Braz, O., Dammertz, G., Iatrou, C. T., Illy, S., Kuntze, M., et al. (1999). Thumm, M.:165 GHz, 1.5 MW—Coaxial gyrotron with depressed collector. IEEE Transactions on Plasma Science, 27(2), 484–489.CrossRefGoogle Scholar
  10. 10.
    Saraph, G. P., Felch, K. L., Feinstein, J., Borchard, P., Cauffman, S. R., & Chu, S. (2000). A comparative study of three single-stage, depressed-collector designs for a 1-MW, CW gyrotron. IEEE Transactions on Plasma Science, 28(3), 830–840.CrossRefGoogle Scholar
  11. 11.
    Pagonakis, I. G., Illy, S., Ioannidis, Z. C., Rzesnicki, T., Avramidis, K. A., Gantenbein, G., et al. (2018). Numerical investigation on spent beam deceleration schemes for depressed collector of a high-power gyrotron. IEEE Transactions on Electron Devices.Google Scholar
  12. 12.
    User Manual Computer Simulation Technology (CST) Studio Suite 2016, Darmstadt, GmbH, Germany (2016).Google Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.Microwave Tube Research and Development CentreBangaloreIndia

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