The experimental setup of a gyrotron which operates in the TE0,3 mode is described. The results of measurements with several gyrotron versions at short pulses (0.5 ms) and long pulses (100 ms) are reported. Designs for higher powers (up to 1 MW) using a nonsymmetric volume mode are presented. First experiments will use the TE10,4 mode. A quasioptical convertor for the output mode will be used, either in conjunction with an axial window or, later, with a radial window.
"140 GHz gyrotron development at KfK Karlsruhe", Proc. SPIE 1514, 15th International Conference on Infrared and Millimeter Waves, 15144C (1 December 1990); doi: 10.1117/12.2301566; https://doi.org/10.1117/12.2301566