Current status of the new ECRH system for ASDEX upgrade

The first two-frequency gyrotron has been installed in the new multi-frequency ECRH system at the ASDEX Upgrade Tokamak experiment. In its final stage the system consist of 4 gyrotrons, tunable in the range 105-140 GHz with a total power of 4 MW and a pulse length of 10 s. It employs a fast steerable launcher for feedback controlled deposition that allows for poloidal steering of 10/spl deg/ within 100 ms. Transmission line elements, such as corrugated waveguides, polarizer mirrors and vacuum windows, are designed to cope for this frequency band.