High priority R&D topics in support of ITER diagnostic development

Donn, A. J. H.*; Costley, A. E.*; ITPA Topical Group on Diagnostics*

The development of diagnostics for ITER is a major challenge because of the harsh environment, strict engineering requirements and the need for high reliability in the measurements. A number of R&D tasks have been identified by the International Tokamak Physics Activity (ITPA) as "high priority" and form the focus of current work: (1) Review the requirements for measurements of the neutron/alpha particle source profile and assess possible methods of measurement, (2) Development of methods to measure the energy and density distribution of confined and escaping a-particles, (3) Determine any additional tests and measurements needed of the irradiation effects on candidate materials and sensors used for diagnostic construction, (4) Determine the life-time of plasma facing mirrors used in optical systems, (5) Develop the requirements for measurements of dust, and assess candidate techniques for the measurement of dust and erosion, (6) Assess the effects of radiation on magnetic coils used for measurements of the plasma equilibrium and support the development of new methods to measure steady state magnetic fields accurately in a nuclear environment. This paper will report on recent achievements in these tasks.