The GT92-5P/2 is a Quasi-Optical Gyrotron which shall proof that such a device is a useful and well developed tool for fusion plasma heating. Two resonators inside the vacuum vessel make it possible to operate it at 92 GHz as well as at 185 GHz. The power expected at fundamental is 500 kW, at a pulse length of 10 ms. Many new features, such as diffraction coupling mirrors and attenuated meshed beam ducts are introduced to guarantee reliable operation.
B. Jodicke, B. Jodicke,
"500 kW quasi-optical gyrotron for 92 and 185 GHz", Proc. SPIE 1514, 15th International Conference on Infrared and Millimeter Waves, 15142I (1 December 1990); doi: 10.1117/12.2301500; https://doi.org/10.1117/12.2301500