Development and First Operation of the 170 GHz, 2 MW Longer-Pulse Coaxial-Cavity Modular Gyrotron Prototype at KIT

Karlsruhe Institute of Technology (KIT) is progressing in the development of a multi-megawatt class gyrotron for fusion plasma applications. After the successful experimental verification of the performance of the modular KIT 170 GHz, 2 MW short-pulse coaxial-cavity pre-prototype gyrotron with pulse lengths up to a few ms, the key gyrotron components have been upgraded by adding suitable cooling systems, keeping their previously validated scientific design. The new gyrotron construction allows the operation with pulses up to ~100 ms, however further increase of the pulse length is planned, after the installation of a diamond window and an improved collector. The basic upgrade of the individual components, the final assembly and the first experimental results are presented.