90% Efficient Two-Stage Multibeam Klystron: Modeling and Design Study

The efficient generation of microwave power has recently gained broad attention in the accelerator community because energy consumption is one of the major concerns for future large-scale high-energy accelerator projects. For the first time, we present a concept of the two-stage multibeam klystron with annular beams (TS MABK). It allows for a remarkably high RF power production efficiency (90%), using a compact design and delivering a cost-effective electro-mechanical solution. The design is for a 1-GHz, 20-MW klystron. The performance of the tube is validated using particle-in-cell computer simulations. In this article, we focus on technological novelties and on mitigation of specific issues.