Multi-frequency design of a 2 MW coaxial-cavity gyrotron for DEMO

The Karlsruhe Institute of Technology (KIT) is working on a possible physical design of 2 MW coaxial-cavity gyrotrons for future fusion applications, initially considering a first demonstration fusion power plant (DEMO). One focus of the investigations is how successfully such gyrotrons can be operated at significantly different frequencies. The gyrotron design as presented here is optimized for operation at one very high order main cavity mode around 237.5 GHz, with secondary modes at 170.0 GHz and 203.8 GHz. The considered technical design restrictions as well as simulation results are presented.