Design of the Remote-Steering ITER ECRH Upper-Port Launcher

The design of the mm-wave system for the ITER upper ports is being carried out with the aim to inject Electron Cyclotron Waves (ECW) in the plasma in order to stabilize neoclassical tearing modes (NTM). Four upper ports are equipped with six mm-wave lines, each capable of transmitting up to 2 MW at 170 GHz. The required beam-steering capabilities es in our approach are achieved by Remote Steering (RS). New design efforts are presented that improve the current-drive capability of the RS set-up substantially by doubling the square waveguide length to around 9 m.