Speaker
Jorge M. Santos
(Instituto de Plasmas e Fusao Nuclear)
Description
On future long pulse fusion devices an extended set of diagnostics will play an increasingly important role in advanced plasma control. In particular, O-mode microwave reflectometry will be used, on ITER and foreseeably on DEMO, to complement the standard magnetic diagnostics for plasma position control. With the preliminary design of ITER’s plasma position reflectometers (PPR) presently underway, it is of the utmost interest to test beforehand all possible aspects of this future control application. ASDEX Upgrade is the best suited experimental facility on which such tests can be performed. Not only it features a modern, modular and easy adaptable control system, but also the only O-mode reflectometry setup capable of performing simultaneously measurements on two of the four lines of sight of ITER’s PPR.After the first successful demonstration of plasma position control using Low-field side (LFS) reflectometry density profile data, the real-time (RT) diagnostic’s hardware was updated to acquire a higher number of signals and to improve its RT data-processing capabilities. Meanwhile, the system’s software was rewritten to implement a pipelined architecture that improves the deterministic behavior of the diagnostic’s internal data flow, from data acquisition up to control data delivery to the AUG discharge control system (DCS). The pipeline last stage, that calculates the control relevant parameters, synchronizing and communicating with the DCS, now uses the new DCS software framework, appearing to the DCS infrastructure as a modular plugin RT diagnostic “App Process”. Herein are discussed the performance and reliability gains obtained with this new software implementation. Fault tolerance, measurement rate and implementable synchronization strategies allowed by the new DCS infrastructure are also addressed. Experimental data from discharges where reflectometry is used for controlling both plasma position and shape are presented to assess the system “real life” performance.
Co-authors
ASDEX Upgrade Team
(Max-Planck-Institut fuer Plasmaphysik, Garching D-85748, Germany)
Antonio Silva
(Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, P-1049-001 Lisboa, Portugal)
Chris Rapson
(Max-Planck-Institut fuer Plasmaphysik, Garching D-85748, Germany)
Goncalo Santos
(Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, P-1049-001 Lisboa, Portugal)
Jorge M. Santos
(Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, P-1049-001 Lisboa, Portugal)
Luis Guimarais
(Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, P-1049-001 Lisboa, Portugal)
Manfred Zilker
(Max-Planck-Institut fuer Plasmaphysik, Garching D-85748, Germany)
Wolfgang Treutterer
(Max-Planck-Institut fuer Plasmaphysik, Garching D-85748, Germany)
