Status of the new ECRH system for ASDEX Upgrade

A new ECRH system is currently being constructed at ASDEX Upgrade with a total power of 4 MW and pulse length of 10 s. The power will be generated by four gyrotrons which can work either at two frequencies (2f-gyrotron), 105 or 140 GHz, or step-tunable at many frequencies within this range (mf-gyrotron). The transmission line and its components are especially designed to cope with the wide frequency range. A fast poloidal mirror steering will be used for feedback controlled power deposition, particularly in experiments on suppression of neoclassical tearing modes.