Development of Multi-Frequency (105-140) GHz Gyrotron

The paper presents last time achievement in the development of a step tunable multi-frequency gyrotron with a megawatt power level. The mock-up of such gyrotron with a new principle broadband electrodynamics system containing Brewster output window was successfully tested. In the frequency range (100-150) GHz the generation of power exceeding 1 MW was demonstrated at 6 frequencies with a very low (about 2{\%}) internal diffraction losses. On the basis of this result industrial gyrotron with a CVD diamond output window was constructed for 10 sec operation. The full time tests are planned for September 2007.