Fast elaboration of diagnostic data for real time control in FTU tokamak
1 Associazione EURATOM-ENEA, IFP-CNR, Milano, Italy
2 Associazione EURATOM-ENEA, C.R. Frascati, Italy
a e-mail : firstname.lastname@example.org
The automatic controller developed for MHD instability control on FTU via the real time (RT) EC launcher [1, 2] is based on the a-priori estimate of the instabilities location and on the fast elaboration of the stream of diagnostic data. A fast data acquisition system, based on existing standard FTU diagnostics, collects thermal and magnetic signals by a 12-channels ECE polychromator  and by a set of 22 Mirnov coils respectively. Moreover, the EC time waveform from directional couplers along the transmission line is acquired as well. This set of signals is processed in a timescale significantly shorter than the typical time step of the controller (1ms). RT elaboration algorithms aim at supplying the controller  with reliable information about the existence and the spatial location of the instability and about the actual ECRH deposition layer in plasma. The main algorithms blocks are ECE-ECE, ECE-Mirnov and ECE-ECRH cross-correlation, and SVD (Singular Value Decomposition) of Mirnov signals. The capabilities of effective detection, false positive resilience, and mode discrimination will be discussed through the application to actual plasma data.
© Owned by the authors, published by EDP Sciences 2012