Choice of material composition for a high-performance inverted Magnetron Injection Gun

An inverse Magnetron Injection Gun (IMIG) has been designed for the KIT 2 MW, 170 GHz coaxial cavity gyrotron. The ambition is the possibility for implementation of a larger emitter ring compared to the “conventional” MIGs used in today's fusion gyrotrons. Considering the fundamental beam parameters, in the theoretical analysis an excellent beam quality has been achieved which results in a very low velocity spread. In order to ensure a stable operation under hot condition, the thermomechanical behavior and material compositions were investigated and optimized.