Asian Journal of Physics Vol 32, Nos 9 – 12 (2023) 539-544

Design and simulation studies of a Ka-band two-cavity gyro-twystron amplifier

V Veera Babu, Shyam Gopal Yadav, Smrity Dwivedi, and M Thottappan
Center of Research in Microwave Tubes (CRMT), Department of Electronics Engineering,
Indian Institute of Technology (BHU), Varanasi-221 005. India.
Dedicated to Prof B N Basu

In this paper, the behavior of 3D beam-wave interaction of a 35 GHz two-cavity gyro-twystron amplifier is studied using particle-in-cell (PIC) solver of CST Particle Studio. Modelling and beam-absent (cold simulation) study of the RF interaction structure is carried out to ensure the favorable propagation characteristics. The performance metrics of a two-cavity gyro-twystron is investigated in the presence of gyrating electron beam with velocity spread of around 4% . The PIC simulation of the amplifier predicted ~ 260 kW of peak output power at 35 GHz, operating in TE01 mode, with a gyrating electron beam of 68 kV potential carrying 9A of current. The power gain of the amplifier is calculated as ~ 57 dB and the conversion efficiency of ~ 42%. © Anita Publications. All rights reserved.
Keywords: Gyro-Twystron, Particle-in-cell simulation, PIC Simulation, Ka-band amplifier.

Peer Review Information
Method: Single- anonymous; Screened for Plagiarism? Yes
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  1. Thumm M, State-of-the-art of high-power gyro-devices and free electron maseres update 2013, Institut für HochleistungsimpulsundMikrowellentechnik (IHM) Karlsruhe Inst. Technol., Karlsruhe, Germany, KIT Sci Rep, (2014)7662.
  2. Nusinovich G S, Li H, Theory of the relativistic gyrotwistron, Phys Fluids B, 4(1992)1058–1065.
  3. Kartikeyan M V, Borie E, Thumm M K A, Gyrotrons, (Springer–Verlag),2004.
  4. Tran T M, Kreischer K E, Temkin R J, Theory of harmonic gyro-twystron, MIT Plasma Science and Fusion Center 1985.
  5. Choi J J, McCurdy A H, Wood F N, Kyser R H, Calame J P, Nguyen K T,  Danly B G, Antonsen T M, Levush B, Parker R K, Experimental investigation of a high power, two-cavity, 35 GHz gyroklystron amplifier, IEEE Trans Plasma Sci, 26(1998)416–425.
  6. Calame J P, Garven M, Choi J J, Nguyen K, Wood F, Blank M, Danly B G, Levush B, Experimental Studies of bandwidth and power production in a three-cavity, 35 GHz gyroklystron amplifier, Phys Plasmas,  6(1990)285–297.
  7. Garven M, Calame J P, Danly B G, Nguyen K, Levush B, Wood F N, Pershing D E, A Gyrotron Travelling Wave Tube Experimental Amplifier Experiment with a ceramic loaded interaction region, IEEE Trans Plasma Sci, 30(2002)885–893.
  8. Kou C S, Wu M H, Tseng F, Nonlinear analysis of a multi-cavity gyro-twystron, Int J Infr Millim Waves, 8(1997)1857–1883.
  9. CST-Particle Studio, User’s Manual, Darmstadt, Germany, 2022.
  10. Di J, Zhu D.-J, Liu S.-G, Electromagnetic field algorithms of chipic code, J Univ Electron Sci Technol China, 34(2005)485–488.
  11. Petillo J J, Mankofsky A, Krueger W A, Kostas C, Mondelli A A, Drobot A T, Applications of the ARGUS code in accelerator physics, AIP Conf Proc, 297(1993)303–312.
  12. Nguyen K T, Levush B, Antonsen T M, Botton M, Blank M, Calame J P, Danly B G, Modeling of gyroklystrons with MAGY, IEEE Trans Plasma Sci, 28(2000)867–886.
  13. Warren G, Ludeking L, Nguyen K, Smithe D, Goplen B, Advances/applications of MAGIC and SOS, AIP Conf Proc, 297(1993)313–322.
  14. Choi J, A high-gain, 28 GHz, 200 kW gyroklystron amplifier, Int J Infr Millim Waves, 19(1998)1681–1691.
  15. Chu K R, Granatstein V L, Latham P E, Lawson W, Striffler C D, A 30-MW gyroklystron-amplifier design for highenergy linear accelerators, IEEE Trans Plasma Sci, 6(1985)424–434.