ARIES-ST plasma-facing component design and analysis

ARIES-ST is a 1000 MW fusion power plant conceptual design based on a low a spect ratio 'spherical torus' (ST) plasma. The plasma-facing components inc lude the inboard and outboard first wall, divertor plates, and plasma stabi lity plates. Several unique aspects of ST plasma influence the engineering design. The limited inboard space precludes a full inboard divertor slot, s uch that substantial power and particle flows are expected to impact the in board first wall. Strong requirements on plasma vertical stability require close-in conductors. The use of He-cooled tungsten for the stability plates allows them to act as plasma-interactive components operating at high temp erature and moderately high (1-2 MW/m(2)) heat flux. High plasma core radia tion fraction and a natural tendency for low inboard transport losses help to alleviate these inboard problems, such that the peak power loads are not expected to exceed the capability of He-cooled tungsten and steel structur es. The main features of the plasma-facing components are summarized here t ogether with the analysis of their thermal hydraulic and thermomechanical p erformance. (C) 2000 Elsevier Science B.V. All rights reserved.