Tracer techniques for the assessment of material migration and surface modification of plasma-facing components
2015 (English)In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 463, 280-284 p.Article in journal (Refereed) Published
Tracer techniques were used in the TEXTOR tokamak to determine high-Z metal migration and the deposition of species used for plasma edge cooling or wall conditioning under different types of operation conditions. Volatile molybdenum hexa-fluoride, nitrogen-15 and oxygen-18 were used as markers in tokamak or ion cyclotron wall conditioning discharges (ICWC). The objective was to obtain qualitative and quantitative of a global and local deposition pattern and material mixing effects. The deposition and retention was studied on plasma-facing components, collector probes and test limiters. Optical spectroscopy and ex-situ analysis techniques were used to determine the plasma response to tracer injection and the modification of surface composition. Molybdenum and light isotopes were detected on all types of limiters and short-term probes retrieved from the vessel showing that both helium and nitrogen are trapped following wall conditioning and edge cooling. Only small amounts below 1 x 10(19) m(-2) of O-18 were detected on surfaces treated by oxygen-assisted ICWC.
Place, publisher, year, edition, pages
2015. Vol. 463, 280-284 p.
Materials Engineering Fusion, Plasma and Space Physics
IdentifiersURN: urn:nbn:se:kth:diva-172689DOI: 10.1016/j.jnucmat.2014.11.074ISI: 000358467200052ScopusID: 2-s2.0-84937517699OAI: oai:DiVA.org:kth-172689DiVA: diva2:850225
FunderSwedish Research Council, 621-2009-4138
QC 201509012015-09-012015-08-272015-12-03Bibliographically approved