Feedback control of resistive modes in tokamaks
The control of the amplitude of rotating resistive modes is important in order to prevent disruptive conditions, thereby extending the operating space of tokamaks. To gain information for the design of practical feedback schemes, it is useful to analyse the response of non-linear modes to time dependent boundary conditions imposed by external conductors and a resistive vessel. It is shown how a dynamic system describing the evolution of the amplitude and the phase of the modes is obtained. The system presents regimes of both phase and frequency instabilities and shows clearly that the problem of amplitude stabilisation is strictly related to the stabilisation of the phase.
Bibliographic Reference: Report: JET-P(89)33 EN (1990) 29 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199011432 / Last updated on: 1994-12-02
Original language: en
Available languages: en