High power system for ECRH at 140Ghz, 2MW, 0.5s on FTU tokamak

The 140GHz, 2MW, 0.5s ECRH system on FTU tokamak integrates closed waveguide transmission lines (≈30 m) with quasi optical systems at both ends for efficient coupling from the 4 gyrotrons to the 4 waveguides and from these to the plasma through a single access port. Poloidal and toroidal control of the beam’s launching angles and polarization is performed without movable components close to the plasma. Most of the components of each generation and transmission system were designed to operate at a power level higher than 0.5 MW, and a possible up-grade to a full 1 MW, 0.5 s capability is discussed.