Development of output section for S-band broadband high-average-power klystron

The output section used in an S-band high average power klystron with 7.1% bandwidth is investigated. It adopts the two-gap overlapping-mode coupled cavity which uses the short slot coupled mode. The dimension of the coupled slot is obtained by formula, and the two cavities’ parameters of frequency, quality factor, and two gap centers’ distance are chosen generally. According to the above parameters, the cold-test model is processed. The slot’s resonant frequency and coupling coefficient derived by the cold test have an error of 2.5% compared with the original design values, the calculated impedance matrix curve has the same direction as the cold-test relative impedance curve, and the calculated power and the hot-test results satisfy the design requirements of more than 1.1 MW peak powe