بررسی اجمالی مواد اولیه اخیر اروپایی ،فعالیت های R & D مربوط به ITER

An overview is given of the wide range of activities contained within recent R&D being performed within Europe on In-vessel materials for structural, heat sink and plasma facing purposes for ITER. The effect of creep-fatigue interaction on the fatigue life of CuCrZr and the effects of irradiation on over-aged CuCrZr are given. In addition the lifetime of ITER components has been further investigated by the performance of in situ experiments with both neutrons and high-energy protons. The effect of hydrogen on the crack initiation fracture toughness of Ti is reported at a range of irradiation temperatures. The irradiation induced stress relaxation of Alloy 718 used for bolting applications is being studied and initial results will be described. Work in the area of plasma facing materials and re-welding issues will also be presented.

The materials chosen for ITER have been selected, as far as possible, from conventional, well-characterised materials. Given this fact, however, a significant amount of materials R&D activities were needed for ITER. Some of the main reasons for this have been: the relatively high neutron fluence at the First Wall, the evolving nature of the ITER design, the selection of materials from competing alternatives proposed by the different parties and the development of new manufacturing routes for In-vessel components. Changes in the design of some of the components aimed at reducing the cost of construction has also had an impact on some of the materials used. As the construction of ITER imminent it is an appropriate time to review the materials data available to support the design of components for ITER. This review is being performed in the ITER framework [1]. However, R&D results are still becoming available and this paper will describe the recent R&D performed within Europe for ITER in the vessel/In vessel field and indicate where work is still under way. The order of the work described will start at the outside of the machine and work inwards towards the plasma from the vacuum vessel to the plasma facing materials. The paper will concentrate on the effect of irradiation on the material properties.