Key issues in ITER diagnostics: Problems and solutions (invited)

The key problems associated with designing diagnostic systems for the Inter national Thermonuclear Experimental Reactor (ITER) are identified and repre sentative solutions are described. The plans for dealing with some outstand ing issues are briefly presented. The detailed work is specific to the ITER , but much of what has been learned will be applicable to any reactor grade tokamak plasma. (C) 1999 American Institute of Physics. [S0034-6748(99)545 01-2].