Influence of temperature and plasma composition on deuterium retention in refractory metals

TitleInfluence of temperature and plasma composition on deuterium retention in refractory metals
Publication TypeJournal Article
Year of Publication2010
AuthorsE. Alves, L.C Alves, N.P Barradas, R. Mateus, P.A Carvalho, G.M Wright
JournalNuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms
Date PublishedJun
Type of ArticleProceedings Paper
ISBN Number0168-583X
Accession NumberISI:000278702300094
KeywordsDEUTERIUM RETENTION, Plasma facing materials, Plasma irradiation, Tungsten

Refractory materials are being considered potential candidates to build the first wall of the fusion reactor chamber. This work reports on the results of the study of tungsten and molybdenum metals exposed to high flux densities (similar to 10(24) D/m(2) s) and low temperature (T-e similar to 3 eV) deuterium plasmas in Pilot-PSI irradiation facility. The hydrogenic retention in poly-crystalline W and Mo targets was studied with He-3 nuclear reaction analyses (NRA). The NRA results clearly show a two-dimensional radial distribution of the deuterium with a minimum at the center and a maximum close to the edge. These distribution correlates well with the thermal profile of the sample surface, where a maximum of similar to 1600 K was measured at the center decreasing to similar to 1000 K in the edges. A maximum deuterium fluence retention of 5 x 10(15) D/cm(2) was measured. The values of the retained fractions ranging from 10(-5) to 10(-6) D-retained/D-incident were measured with thermal desorption spectroscopy (TDS) and compares well with IBA results. Moreover, the presence of C in the plasma and its co-deposition increases the D retention in the region where a C film is formed. Both NRA and TDS results show no clear dependence of retention on incident fluence suggesting the absence of plasma related traps in W under these conditions. (C) 2010 Elsevier B.V. All rights reserved.

URL<Go to ISI>://000278702300094

Fusion Physics





Alternate TitleNucl. Instrum. Methods Phys. Res. Sect. B-Beam Interact. Mater. Atoms

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