Engineering analysis has been carried out on a representative equatorial diagnostic port plug of ITER, outcome of which is given here. A preliminary overview of the work for a prototypical diagnostic upper port plug is also reported. To ensure that the port plug structure satisfies the requirements of the ITER environment, the following analyses have been performed: finite element (FE) analyses of static and dynamic behaviour under electromagnetic loads, FE vibration analysis, FE thermal-structural analysis and nuclear heating and radiation dose studies.The main outcomes from these analyses and consequent design developments are a revision of the stainless steellwater ratio in the plug neutron shielding modules and the incorporation of improved neutron shielding of the port duct, a modification of the port plug top plate arrangement, to increase torsional stiffness of the structure under disruption loads, and improved solutions for cooling arrangements. Manufacturing studies have also been performed, involving the assessment of methods for the production of plug flanges, the analysis of welding techniques for parts assembly and methods for the introduction of cooling features in plug components. Reference design solutions and possible modifications will be presented and discussed. (C) 2007 Published by Elsevier B.V.

The European Union will supply a number of diagnostics for ITER. Significant progress has been made on the design and integration of these diagnostics. Specific topics, in common for several of the diagnostics, discussed are port-plug integration, simplification of labyrinths against neutron streaming, and design measures to protect and to be able to replace sensitive optical components. Performance analysis to predict the likely capability of the diagnostics to meet the ITER measurement requirements will be an important aspect of the design process. The interpretation of the measurement requirements, specifically of spatial resolution in the case of indirect measurements, is discussed on the basis of two examples, and methods of performance analysis are compared.