On forced RF generation of CW magnetrons for SRF accelerators

Conference · Thu Sep 05 04:00:00 EDT 2024

DOI:https://doi.org/10.2172/2440237· OSTI ID:2440237

Kazakevich, G. ^[1]; Johnson, R. P. ^[1]; Khabiboulline, T. ^[2]; Romanov, G. ^[2]; Yakovlev, V. ^[2]; Derbenev, Ya. ^[1]

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1. Jefferson Lab
2. Fermilab

CW magnetrons, initially developed for industrial RF heaters, were suggested to power RF cavities of superconducting accelerators due to their higher efficiency and lower cost of RF power per Watt than used traditionally klystrons, IOTs or solid-state amplifiers. RF amplifiers driven by a master oscillator serve as coherent RF sources. CW magnetrons are regenerative RF generators with a huge regenerative gain to start up reliably with self-excitation even if the tube is powered by a DC power supply. This causes regenerative instability with a large noise when a magnetron operates with the anode voltage above the threshold of self-excitation. Traditionally for stabilization of magnetrons is used injection locking by a signal PLock ≤ -20 dB or less then of the magnetron power PMag. Then the magnetron generates the injection locked oscillations and generates noise. This may preclude use of standard CW magnetrons in some SRF accelerators. We developed briefly described below a mode for forced coherent RF generation of CW magnetrons when the magnetron startup is provided by the injected forcing signal and the regenerative noise is suppressed. The mode is most suitable for powering high Q-factor SRF cavities.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 2440237
• Report Number(s): FERMILAB-POSTER-24-0248-TD; oai:inspirehep.net:2825197
• Country of Publication: United States
• Language: English