Demonstration of efficient beam-wave interaction for a MW-level 48 GHz gyroklystron amplifier

Nix, L. J. R. and Zhang, L. and He, W. and Donaldson, C. R. and Ronald, K. and Cross, A. W. and Whyte, C. G. (2020) Demonstration of efficient beam-wave interaction for a MW-level 48 GHz gyroklystron amplifier. Physics of Plasmas, 27 (5). 053101. ISSN 1070-664X (

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The development of high-frequency RF linear accelerators (linacs) requires the consideration of several technological challenges, such as electron bunch linearization. Presented in this paper is the design of the interaction circuit for a 48 GHz MW-level three-cavity gyroklystron amplifier, appropriate for application as a millimeter wave power source in a fourth harmonic linearizing system for an X-band linac. The output cavity is operated at the cylindrical TE0,2,1 mode, while the input and buncher cavities are operated at the TE0,1,1 mode. The interaction circuit has been designed using a combination of analytical calculations and particle-in-cell simulations. The optimized gyroklystron is shown, through simulation, to deliver an output power of up to 2.3 MW with a gain of 36 dB and an efficiency of 44% at 48 GHz, when driven by a 140 kV, 37 A electron beam. The   support   of   the   STFC   UK (Cockcroft Institute Core GrantR160525-1) is gratefully acknowledged. This  work  is  supported  by European Union (EU) Horizon 2020 Project  “CompactLight” 2017-2021. “CompactLight”  grant code: 777431-XLS. Published data March 2020, under Self-archiving / 'green' OA.


Nix, L. J. R., Zhang, L. ORCID logoORCID:, He, W., Donaldson, C. R. ORCID logoORCID:, Ronald, K. ORCID logoORCID:, Cross, A. W. ORCID logoORCID: and Whyte, C. G. ORCID logoORCID:;