A high power cross-field amplifier at X-band

A high power cross-field amplifier (CFA) is under development at SLAC to provide sufficient peak power to feed a section of an X-band accelerator without the need for pulse compression. The CFA employs a conventional distributed secondary emission cathode and a novel anode structure which consists of an array of vane resonators alternatively coupled to a rectangular waveguide. The waveguide impedance is tapered linearly from input to output to provide a constant RF voltage at the vane tips, leading to uniform power generation along the structure. Nominal design for this tube calls for 300 MW output power, 20 dB gain, a DC voltage of 142 kV, a magnetic field of 5 kG, an anode-cathode gap of 3.6 mm, and a total interaction length of about 60 cm. The authors have used ARGUS to model the cold circuit properties and CONDOR to model the electronic power conversion. An efficiency of 60% is expected. The design effort is discussed.<>