A New ECRH System for ASDEX Upgrade
F.Leuterer, K.Kirov, F.Monaco, M.Münich, H.Schütz, F.Ryter, D.Wagner, R. Wilhelm, H.Zohm, T.Franke, K.Voigt
3) Universität Karlsruhe, Institut für Höchstfrequenztechnik und Elektronik
D-76128 Karlsruhe, Germany
A.Bogdashov, G.Denisov, V.Kurbatov, A.Kuftin, A.Litvak
A new ECRH system is currently under construction at ASDEX Upgrade with a total power of 4 MW, generated by 4 gyrotrons, and a pulse length of 10 sec. A particular feature is the use of multifrequency gyrotrons, where the gyrotrons will work either at two frequencies (104/140 GHz) or will be step-tunable in the range 104-140 GHz. The system should allow for central heating at different magnetic fields. It will also give more flexibility for the stabilization of neoclassical tearing modes (NTM) through the possibility of current drive on the high field side without changing the magnetic field and very localized feedback controlled power deposition with a narrow beamwidth by using a fast steerable launcher.