Plasma and Fusion Research

Volume 9, 1405003 (2014)

Regular Articles

Implementation of a Novel Real-Time Controller for the Detection and Tracking of Magneto-Hydrodynamic Instabilities on the JET Tokamak

Duccio TESTA, Hervé CARFANTAN¹⁾, Alex GOODYEAR²⁾ and JET-EFDA contributors³⁾

: Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas (CRPP), Association EURATOM - Confédération Suisse, Lausanne, Switzerland
1): Université de Toulouse, Institut de Recherche en Astrophysique et Planétologie, Centre National pour la Recherche Scientifique, Toulouse, France
2): Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, United Kingdom
3): JET-EFDA, Culham Science Centre, OX14 3DB, Abingdon, UK

(Received 8 October 2012 / Accepted 10 September 2013 / Published 31 January 2014)

Abstract

In this work we present the technical implementation of a digital VERSA Module Eurocard (VMEbus) system used to detect and track, in real-time, magneto-hydrodynamic instabilities on the JET tokamak. This VMEbus system runs on a 1 ms clock cycle and performs the unsupervised detection and real-time tracking of the individual components in a multi-harmonic spectrum of coherent electro-magnetic instabilities, actively driven by a set of in-vessel antennas. Its main real-time output signals are the frequency, amplitude, toroidal mode number and damping rate of such modes. Moreover, this controller also provides some of the protection and control tools for the antenna system, such as the reference for the voltage and current control waveforms, and a trip signal related to the shorted-turn protection of the antennas. Current applications of this novel controller focus on the measurement of the damping rate of Alfvén Eigenmodes with different toroidal mode numbers. The successful technical implementation and scientific exploitation of this innovative VMEbus system opens possibilities for the real-time detection and the ensuing control of electro-magnetic instabilities in other present and future fusion devices.

Keywords

MHD modes, real-time detection, real-time control

DOI: 10.1585/pfr.9.1405003

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This paper may be cited as follows:

Duccio TESTA, Hervé CARFANTAN, Alex GOODYEAR and JET-EFDA contributors, Plasma Fusion Res. 9, 1405003 (2014).