The ITER project has an overall programmatic objective 'to demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes'. The ITER tokamak design is the embodiment of the finding, endorsed by all the parties to the project, that 'the full non-linear interplay between alpha-particle heating, confinement barriers and pressure and profile control, and their compatibility with a divertor can be addressed only in an integrated step'. This step involves not only the study of fusion burning plasma physics but also the demonstration of key items of fusion reactor technology.This paper introduces: magnetic fusion plasma (section 1), the physics goals of ITER (section 2) and the burning plasma physics which will be studied (section 3), examines the present ITER design and how it meets the plasma performance requirements in terms of extended burn at specific fusion power amplification (section 4), describes plasma measurements for ITER and some of the issues involved in their implementation (section 5), indicates how ITER provides a focus for international research into tokamak plasma physics (section 6), and presents a brief report on the status of the ITER Project (section 7). To conclude, this paper presents some final remarks (section 8).

The measurement requirements and expected performance of the International Thermonuclear Experimental Reactor (ITER) magnetics system are summarized. The constraints of a burning plasma experiment (BPX) on tokamak magnetic diagnostic system designs are listed and illustrated using the parameters and design of sensors being developed for the ITER device. Design principles to meet the constraints are discussed, with an emphasis on radiation effects, reliability, and redundancy for sensors and subsystems. The remaining research and development for the ITER system is outlined.

The ITER magnets are long-lead time items and the preparation of their construction is the subject of a major and coordinated effort of the ITER International Team and Participant Teams. The results of the ITER model coil programme constitute the basis and the main source of data for the preparation of the technical specifications for the procurement of the ITER magnets. A review of the salient results of the ITER model coil programme is given and the significance of these results for the preparation of full size industrial production is explained. The model coil programme has confirmed the validity of the design and the manufacturerÕs ability to produce the coils with the required quality level. The programme has also allowed the optimisation of the conductor design and the identification of further development which would lead to cost reductions of the toroidal field coil case.