Development of 1-MW long-pulse/CW gyrotrons in 110-170 GHz frequency range

The given paper represents the review of modern experimental results, design features and perspectives of "GYCOM" gyrotrons further development. 140 GHz and 110 GHz "GYCOM" gyrotrons are used as sources of electron cyclotron resonance heating (ECRH) of plasma on W7-AX stellarator, ASDEX upgrade tokamak (both IPP, Germany), DIII-D tokamak (General atomic, USA), TdeV tokamak (CCFM, Canada). 110-GHz gyrotrons are characterized with the power levels of /spl sim/900 kW for 2-s pulse length and 500 kW for 5-s pulse length. In 140-GHz gyrotron power levels of /spl sim/900 kW for 1-s pulse length, /spl sim/50 kW in 2-s pulses and /spl sim/550 kW 3-s pulses are available. In the first 170 GHz gyrotron experimental sample, developed for the ITER project, the power of 1 MW for 1-s pulse length and 500 kW in 5-s pulses was reached. At the same time, gyrotrons with 1 MIN output power and 50% efficiency in a CW regime should be developed according to request of lTER and programs of modernization for existing installations.