Control of poloidal asymmetry in TEXTOR edge plasma
Under conditions of poloidal asymmetry of plasma in tokamaks, longitudinal equilibrium currents (Pfirsch-Schlüter currents) are closed in a radial direction. In so doing, the force moments I x B(t) for positive and negative values of the radial current I are not equal to the absolute value because of the dependence of the toroidal magnetic field B(t) on the poloidal angle. As a result, plasma rotation must occur. This effect may be especially significant in a scrape-off layer (SOL) where the radial current flowing in the plasma closes on the limiter. Poloidal rotation, in its turn, may change the level of wall turbulence. The rate of poloidal rotation can be controlled by affecting the symmetry, for example, by varying the position of gas puffing. This paper describes the first experiments in varying the poloidal asymmetry of the edge plasma in the TEXTOR tokamak by applying a bias current to the limiter.
Bibliographic Reference: Article: Proceedings of the 20th European Conference on Controlled Fusion and Plasma Physics, Vol. II (1993) pp. 655-658
Record Number: 199311135 / Last updated on: 1994-11-29
Original language: en
Available languages: en