Critical plasma-wall interaction issues for plasma-facing materials and components in near-term fusion devices

The increase in pulse duration and cumulative run-time, together with the i ncrease of the plasma energy content, will represent the largest changes in operation conditions in future fusion devices such as the International Th ermonuclear Experimental Reactor (ITER) compared to today's experimental fa cilities. These will give rise to important plasma-physics effects and plas ma-material interactions (PMIs) which are only partially observed and acces sible in present-day experiments and will open new design, operation and sa fety issues. For the first time in fusion research, erosion and its consequ ences over many pulses (e.g., co-deposition and dust) may determine the ope rational schedule of a fusion device, This paper identifies the most critic al issues arising from PMIs which represent key elements in the selection o f materials, the design, and the optimisation of plasma-facing components ( PFCs) for the first-wall and divertor. Significant advances in the knowledg e base have been made recently, as part of the R&D supporting the engineeri ng design activities (EDA) of ITER, and some of the most relevant data are reviewed here together with areas where further R&D work is urgently needed . (C) 2000 Elsevier Science B.V. All rights reserved.