On the Global Cross-Field Conductivity in SOL of a Tokamak

摘要

A plasma on open field lines that intersects endplates at a shallow angle, as in a tokamak with poloidal divertor, is considered. It is shown that a strong turbulence is likely to develop within the magnetic ion pre-sheath in the vicinity of a divertor plate. The turbulence is anticipated to affect plasma drifts, thereby reducing the current sustainable within the magnetic pre-sheath. The effective thickness of the magnetic pre-sheath is dramatically enhanced due to strong turbulence. Therefore, the classical approach to the issue of the ion current within the magnetic pre-sheath in the context of biasing experiments is subject to serious doubts.