Progress on the ITER Upper Launcher Control Systems
The main objective of the ITER ECRH Upper Launcher (UL) is to control magnetohydrodynamic (MHD) activity: sawtooth oscillations and neoclassical tearing modes. 170GHz RF beams are oriented and focused to obtain a maximum overlapping of the waists of all the beams throughout the deposition location range in the plasma. The steering of the beams is done using 8 independent steering mirrors (SM) placed in the front par t of each one of the four dedicated por t plugs. Accurate and rapid control of the SMs for directing the beams at the required location is crucial in order to achieve an efﬁcient MHD control. An assessment of the SM ﬁrst prototype capabilities to meet the ITER requirements has been carried out giving promising results for this application.