Assessment of erosion and tritium codeposition in ITER-FEAT

Erosion of the first-wall and divertor, and distribution of eroded material in combination with tritium codeposition (primarily with eroded carbon) ov er many pulses, remain critical issues for the design, operation, and safet y of a long-pulse next-step fusion device, such as ITER. These issues are c urrently being investigated by experiments in tokamaks and in laboratories. as well as by modelling. In this study, we analyse erosion (e.g., by sputt ering, ELMs, and off-normal transients) and codeposition effects in the red uced-size ITER' device, called 'ITER-FEAT, with a strike-point carbon diver tor target and metallic walls, for a 'semi-detached' edge plasma regime usi ng two-dimensional profiles of plasma edge parameters, modelled by the code B2-EIRENE. This paper accompanies the overview paper given by G. Janeschit z et al. [Plasma wall interactions in ITER-FEAT, these Proceedings]. Tritiu m codeposition with chemically eroded carbon still presents removal/control challenges, albeit to a somewhat lesser extent than in the 1998 ITER desig n, and demands efficient tritium inventory removal/control techniques. Due to numerous model uncertainties, not the least of which are the plasma solu tions themselves, our intent is to provide a scoping analysis, defining tre nds and suggesting further research needs. (C) 2001 Elsevier Science B.V. A ll rights reserved.