Diagnostics and control for Steady State and Pulsed Tokamak DEMO

The present paper is devoted to a first assessment of the DEMO diagnostics systems and controls. In particular main questions are related to: i) the quantities to be measured in DEMO and the requirements on the measurements; ii) the present capability of the diagnostic and control technology , determining the most urgent gaps and iii) the program of R&D needed to fill the gaps. The perspective of diagnostics and control for DEMO is outlined and some encouraging results emerge from the analysis.Moderated efforts in R&D and estrapolation from ITER technology can be dedicated to Infrared diagnostics ( reflectometry, ECE, polarimetry) and Neutron diagnostics, important for Burn Control , MHD stability, basic machine protection. Metallic Hall sensors appear as candidate for magnetics.