The research on the low peak power Multi-Beam broadband Klystron

One of the research projects of Multi-Beam Klystrons (MBKs) is to extend its bandwidth. The bandwidth of the MBKs strongly depends on its peak power and the cathode loading. In some applications, an S-band MBK with peak power of 30∼50kW, bandwidth of 10%, efficiency of more than 25%, and the lifetime of more than 3000 hours is needed. In order to realize wide bandwidth at low peak power, the S band broadband MBKs with 7 beams are described in this paper. By using seven bunching cavities and a double-gap coupling cavity with π mode RF field structure, this S-band MBK can get bandwidth of ∼10% and efficiency of more than 30%. The cathode loading is chosen at about 10A/cm
²
for getting the lifetime of more than 3000 hours.