Towards an 2 MW long-pulse coaxial-cavity gyrotron: Progress on the advanced KIT inverse magnetron injection gun

An innovative Inverse Magnetron Injection Gun (IMIG) has been designed at KIT. This IMIG will be employed in the modular KIT 2 MW, 170 GHz coaxial-cavity pre-prototype gyrotron. The specific design allows the implementation of a significantly larger emitter ring compared to the “conventional” MIG, considering the same radial dimensions. Due to the direct cooling of the thermally loaded components close to the emitter a significant better temperature profile for those components is achieved. A significant smaller thermal expansion of the electron beam forming components is achieved and the possibility for unwanted emission is reduced. Hence, an excellent electron beam quality under gyrotron operation can be expected. This contribution shows the progress on the manufacturing, assembly and testing.