A real-time instantaneous frequency estimator for rotating magnetic islands in a tokamak thermonuclear plasma

The evolution of rotating magnetic islands is a limit for the regime of stable operation in tokamak plasma confinement systems for nuclear fusion research, working close to operating conditions required in a future reactor. It is possible to counteract the growth of the magnetic islands by applying an external magnetic field, provided that the rotating speed of the magnetic islands is measured. The rotating speed can be determined from the measurement of the frequency of the electromotive force induced on a set of magnetic detectors. This paper proposes a digital method for the estimation of this frequency. The results of some laboratory tests performed on a prototype device of the estimator are reported.<
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