ECE diagnostics for RTO/RC ITER

This paper presents the current status of the Electron Cyclotron Emission ( ECE) diagnostic on the Reduced Technical Objectives/Reduced Cost Internatio nal Thermonuclear Experimental Reactor (RTO/RC ITER). It discusses the impl ications of the new machine design on the measurement requirements, the abi lity of the diagnostic technique to meet these, and the changes in the impl ementation imposed by the new layout. Finally, it outlines the physics stud ies, design and R&D work required prior to the detailed design and construc tion of the diagnostic. Key results are: (i) that the localisation of the m easurement is similar to that in ITER-FDR (40-100 mm in X-mode, 60-200 mm i n O-mode for the reference scenario), so that the relative spatial resoluti on degrades in this, smaller, machine, and (ii) the expected effect of tran sport barriers on the temperature profile in the high temperature region wi ll be poorly resolved, because the effect of the temperature gradient on th e outboard side is to degrade the resolution to (similar to 250 mm in X-mod e, similar to 350 mm in O-mode). Nevertheless ECE will be able to make a un ique and useful contribution to the RTO/RC ITER measurement set. (C) 2001 P ublished by Elsevier Science B.V.