Overview of High Priority ITER Diagnostic Systems Status

Full text: Diagnostics are a critical part of an operational ITER. They will provide all the information on the performance and performance optimisation. At this stage of the tokamak device development, it is imperative that access, boundaries and requirements are well established. This will allow a smooth path towards implementation of the measurement systems as well as minimising effort and ultimately cost. The ITER device will be distinguished by being the largest magnetic fusion device ever built and the first to be licensed as a nuclear facility. It will have operating conditions that have hitherto been unexplored. These include a combination of fusion power and long pulse operation. The combination of the above creates a set of conditions that place many diagnostics in a completely new regime. While optical systems have to access the plasma, they have to also be shielded to avoid direct particulate contamination as well as neutron and mechanical stresses. As well as this, minimisation of activation is required outside the vacuum boundary. These requirements combine to provide a challenging base from which to design the systems. Much R and D is ongoing to provide a sound basis for many of the designs. Specifically a report on upper port engineering, magnetic and infrared systems as well as integration will be presented. (author)