Post mortem analysis of a tungsten coated tile from the outer divertor strike point region of ASDEX upgrade
Elżbieta Fortuna , Mariusz Andrzejczuk , Łukasz Ciupiński , Krzysztof Rożniatowski , Kazuyoshi Sugiyama , M. Mayer , Krzysztof Kurzydłowski
AbstractIn the present study, the structure and the composition of co-deposited layers developed at the outer divertor strike point tile 1 in ASDEX Upgrade during three campaigns from 2009 to 2013 were examined. The samples were cut from representative locations which differed in received flux: private flux, strike point, the highest plasma fluence and “moderate" flux regions. High resolution scanning (SEM) and transmission electron microscopy (HRSTEM) combined with energy-dispersive X-ray spectroscopy (EDS) and optical profilometry have been used to identify deposits composition and morphology as well as to assess coating degradation. The aim of the post-mortem analyses was the evaluation of materials mixing and evidence of plasma-induced damage. Our results confirm that the outer divertor of AUG is generally a net erosion region for tungsten, however, the strong deposition of eroded tungsten takes place close to the outer strike point (private flux region). The observations on cross-sections of the tungsten coatings revealed micro-cracks around the strike point region. These cracks are caused by thermal stresses due to periodic heating and cooling of the layer during ELMs.
|Journal series||Nuclear Materials and Energy, ISSN 2352-1791|
|Publication size in sheets||0.5|
|Keywords in Polish||Erozja, Redepozycja, Popielnik, Mikroskopia elektronowa, ASDEX, Trwałość PFCs|
|Keywords in English||Erosion; Re-deposition; Divertor; Electron microscopy; ASDEX-Upgrade; PFCs lifetime|
|Score|| = 0.0, 28-11-2017, ArticleFromJournal|
= 5.0, 28-11-2017, ArticleFromJournal - czasopismo zagraniczne spoza list
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