This title appears in the Scientific Report : 2010 

Real-time control of tearing modes using a line-of-sight electron cyclotron emission diagnostic
Hennen, B.A.
Westerhof, E. / Nuij, P.W.J.M. / Oosterbeek, J.W. / de Maar, M.R. / Bongers, W.A. / Bürger, A. / Thoen, A. / Steinbuch, D. / TEXTOR, Team.
Plasmaphysik; IEK-4
Plasma physics and controlled fusion, 52 (2010) S. 104006
Bristol IOP Publ. 2010
Journal Article
Plasma Physics and Controlled Fusion 52
Please use the identifier: in citations.
The stability and performance of tokamak plasmas are limited by instabilities such as neoclassical tearing modes. This paper reports on an experimental proof of principle of a feedback control approach for real-time, autonomous suppression and stabilization of tearing modes in a tokamak. The system combines an electron cyclotron emission diagnostic for sensing of the tearing modes in the same sight line with a steerable electron cyclotron resonance heating and current drive (ECRH/ECCD) antenna. A methodology for fast detection of q = m/n = 2/1 tearing modes and retrieval of their location, rotation frequency and phase is presented. Set-points to establish alignment of the ECRH/ECCD deposition location with the centre of the tearing mode are generated in real time and forwarded in closed loop to the steerable launcher and as a modulation pulse train to the gyrotron. Experimental results demonstrate the capability of the control system to track externally perturbed tearing modes in real time.