engleski

IBA for materials analysis in fusion research

The interaction between the confined hot plasma in a controlled fusion device and the surrounding vessel walls is a major challenge on the road to a successful use of fusion energy. First wall materials undergo serious modification by physical and chemical processes arising from plasma–wall interactions. This includes material erosion, transport of eroded material in the plasma and re-deposition leading to the formation of mixed-material layers, and accumulation of hydrogen isotopes including tritium in the wall materials by implantation, diffusion and co-deposition. The understanding of these processes is crucial for the economy and safety of reactor operation. Ion Beam Analysis (IBA) techniques play a particularly prominent role in the analysis of first wall materials due to their sensitivity for individual isotopes in the low-Z range up to 10 (especially for D, T, Be and tracer isotopes such as 13C or 15N), high sensitivity, absolute quantification without the need for reference samples, applicability to rough or multi-phase samples, and the possibility to use several methods in a single run. The analysis of first wall materials is challenging not only for the analytical but also for the technical capabilities due to the broad range of isotopes and elements, the need of analysis of rough samples with technical surfaces, handling of large and heavy sample with sizes up to more than 30 cm and weights of several kg, and handling of hazardous and radioactive materials such as beryllium and tritium. The IAEA Technical Meeting on “Advanced Methodologies for the Analysis of Materials in Energy Applications Using Ion Beam Accelerators” [1] took place in October 2018 and reviewed the current status of ion beam analysis techniques for the field of materials relevant to fusion. Available facilities, apparatus developments and future research options, challenges and analytical needs were presented and discussed. The high level of international cooperation in fusion research yields advantages by providing a variety of analysis setups optimized for different tasks, but also results in problems of inter-comparability and standardization. To prepare the international ion beam analysis community for these challenges, the IAEA technical meeting concludes the necessity to provide facilities for handling of hazardous materials (tritium, activated samples, beryllium) for existing experiments and ITER ; to determine and possibly evaluate cross-sections and stopping powers for elements and isotopes with relevance for fusion ; to standardize measurement and evaluation procedures ; and to perform an international round-robin test with fusion relevant samples for determining the accuracy and comparability of different laboratories.

IBA ; materials analysis ; fusion research

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