Optimization design of multi-beam cathode for klystron

Microwave tube researchers have paid more attention to multi-beam klystron (MBK) for which have many advantages such as low operating voltage , high perveance , small and light. The premise to fabricate for MBK is to provide a multi-beam cathode (MBC) which should satisfy the following requirements: a) high emissive current density; b) low operating temperature; c) low evaporation of the active materials; d) low power consumption or high emissive efficiency; e) robust structure. As compared to the single-beam cathode (SBC), the MBC is to provide high emissive current density, and the MBC itself has a complex structure and multiple technologies. It is urgent to optimize the MBC structure so as to satisfy the above mentioned demands. The interaction of these factors and the method of optimization are described in this paper, and an example showed that the power consumption of the MBC decreased to 92% at the normal operating temperature after optimization design.