Stabilization of axisymmetric modes in elongated tokamak plasmas using active feedback coils inside and outside the vacuum vessel
The TCV tokamak was designed to create plasmas with a variety of cross-sectional shapes with elongations up to kappa = 3. In this paper the feedback stabilisation of the vertical instability in a highly elongated (kappa = 3) TCV plasma, using a combination of active coils inside and outside the vacuum vessel, is studied. Axisymmetric stability was calculated using the NOVA-W code. In this study it was found that fast internal coils very close to the plasma surface can induce an enhanced deformation of the eigenfunction. This paper also demonstrates that a feedback system using a combination of many flux loops and poloidal B-field pickup coils is susceptible to problems and that a large number of distributed flux and B(p) measurements used to determine vertical position does not always improve matters.
Bibliographic Reference: Article: Proceedings of the 1992 International Conference on Plasma Physics Part I, Vol. 16C (1992) pp. 467-470
Record Number: 199310048 / Last updated on: 1994-11-29
Original language: en
Available languages: en