Divertor Target Heat Load Reduction by Electrical Biasing, and Application to COMPASS-D.

Fielding, S. J. ; Cohen, R. H.

Technical Information Center Oak Ridge Tennessee

关键词: Divertors;    Plasma sheath;    Targets;    Heat flux;    Heat transfer;   

RP-ID  :  DE200515013158

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

A toroidally-asymmetric potential structure in the scrape-off layer (SOL) plasma may be formed by toroidally distributed electrical biasing of the divertor target tiles. The resulting ExB convective motions should increase the plasma radial transport in the SOL and thereby reduce the heat load at the divertor. In this paper we develop theoretical modelling and describe the implementation of this concept to the COMPASS-D divertor. We show that strong magnetic shear near the X-point should cause significant squeezing of the convective cells preventing convection from penetrating above the X-point. This should result in reduced heat load at the divertor target without increasing the radial transport in the portion of the SOL in direct contact with the core plasma, potentially avoiding any confinement degradation. Implementation of divertor biasing is in hand on COMPASS-D involving insulation of, and modifications to the present divertor tiles.