High-Power High-Efficiency L-band Multiple-Beam Klystron Development at CPI
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.
Status of the 805-MHz pulsed klystrons for the Spallation Neutron Source
Communications and Power Industries, Inc (CPI) produced 81 klystrons for the Spallation Neutron Source at Oak Ridge National Laboratory. The klystrons are rated for 550 kW peak at 805 MHz. seventy units have accumulated 1,284,647 hours of filament operation and 820,429 hours of high voltage operation to date. A higher power 700 kW version has been developed and is now in production.
Prediction of net pressure on pressure equalized cavities
Abstract A numerical model has been developed for prediction of net pressure on pressure equalized cavities. The results based on this model show good agreement with those obtained from mock-up tests. Parametric studies verify that reductions in cladding load are possible, with proper design of curtain walls.