e-mail: verhoeven@rijnh.nl www.rijnh.nl
The aim of the mm-wave system to be installed in the
ITER upper-port system is to inject Electron Cyclotron Waves (ECW) in the ITER
plasma in order to stabilize neoclassical tearing modes (NTM). Each upper-port
launcher consists of eight mm-wave lines capable of transmitting high power up
to 2 MW at 170 GHz. Within a broadly based EFDA collaboration conducting design
and R&D activities in preparation for the construction of an ITER upper
port launcher, the FOM institute is leading the mm-wave design activity.
In order to exploit the
capability of ECW for localized heating and current drive over a range of
plasma radii in ITER, the ECH&CD upper port launcher must have a beam
steering capability. To avoid movable mirrors at the plasma-facing end of the
launcher, the concept of remote mm-wave beam steering (RS) is used, having a corrugated
square waveguide within the launcher and the steerable optic is then placed
outside of the first confinement boundary of the vacuum vessel.