Theory Issues for Induced Plasma Convection Experiments in the Divertor of the MAST Spherical Tokamak.

Cohen, R. H. ; Fielding, S. ; Helander, P. ; Ryutov, D. D.

Technical Information Center Oak Ridge Tennessee

关键词: Diverters;    Sheath potential;    Shear flow turbulence;    Magnetic shear;    Criteria;   

RP-ID  :  DE200515013409

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

This paper surveys theory issues associated with inducing convective cells through diverter tile biasing in a tokamak to broaden the scrape-off layer (SOL). The theory is applied to the Mega-Ampere Spherical Tokamak (MAST), where such experiments are planned in the near future. Criteria are presented for achieving strong broadening and for exciting shear-flow turbulence in the SOL; these criteria are shown to be attainable in practice. It is also shown that the magnetic shear present in the vicinity of the X-point is likely to confine the potential perturbations to the diverter region below the X-point, leaving the part of the SOL that is in direct contact with the core plasma intact. The current created by the biasing and associated heating power are found to be modest.