Design of a C-Band Klystron with High Power and High Efficiency

The design of a C-band klystron with high power and high efficiency (HE) is reported in this paper, involving beam-wave interaction, electron optics system (EOS) and RF window. The simulation result of the beam-wave interaction is presented, in which the klystron could deliver up to 48% electronic efficiency and 47% RF efficiency. The pulsed output power is 5.29 MW at the bandwidth of 16 MHz with the gain over 46 dB. The simulation results show that the gun of electron optics system can generate a pencil beam with radius of 4.5 mm, voltage of 130 kV, current of 85 A. Permanent magnet (PM) focusing is adopted in this Klystron, providing a peak magnetic field of 0.26 T in the interaction region. A compact two-stage depressed collector was designed for collecting particles at the end of interaction with thermal dissipation density less than 0.01 kw/cm2. RF window design is also conducted to compete the physical design study of this C-band HE Klystron.