High-Power High-Efficiency L-band Multiple-Beam Klystron Development at CPI

• Published in: IEEE transactions on plasma science Vol. 38; no. 6; pp. 1264 - 1269
• Main Authors: Habermann, Thomas, Balkcum, Adam, Begum, Rasheda, Bohlen, Heinz, Cattelino, Mark, Eisen, Edward, Gajaria, Deepika, Staprans, Armand, Stockwell, Brad, Zitelli, Lou
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Efficiency; Electron linear accelerators; Electron tubes; Free electron lasers; Frequencies; Holes; Klystrons; L-band; Laser modes; Lasers; Linear particle accelerator; Manufacturing; microwave power amplifiers; microwave tubes; Phases; Plasma; Power industry; Prototypes; Pulse measurements; Simulation; Synchrotrons; X-ray lasers
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2010.2042972

Communications and Power Industries, Inc., has designed and manufactured two versions of a 10-MW-peak high-efficiency multiple-beam klystron (MBK) operating at 1300 MHz. This type of klystron is favored for large particle accelerator projects such as the European X-ray Free-Electron Laser at the Deutsches Elektronen Synchrotron (DESY). Two klystrons have been made for DESY. The first-generation MBK was a vertically oriented prototype using a six-cavity design with higher order mode input and output cavities and conventional intermediate cavities. For cost and performance reasons, the second-generation MBK, designated VKL-8301B, utilized seven coaxial fundamental-mode cavities and is an "industrialized" horizontally oriented klystron. The klystron was designed and optimized using state-of-the-art multidimensional design codes to ensure that all performance requirements are exceeded. Agreement between the simulated and measured performances is good. The VKL-8301B prototype achieved a peak saturated RF output power of 10.4 MW and 67.8% efficiency. The data were measured at the full 1.5% duty and with 1.5-ms pulse width. The klystron satisfied all required operating conditions, including stable operation into an output mismatch of 1.2:1 voltage standing wave ratio at various phases. The prototype has been shipped to DESY and has been successfully tested by a customer.