Temperature-dependent in-situ LEIS measurement of W surface enrichment by 250 eV D sputtering of EUROFER

• Main Authors: H.R. Koslowski, S.R. Bhattacharyya, P. Hansen, Ch. Linsmeier, M. Rasiński, P. Ström
• Format: Article
• Language: English
• Published: Elsevier 2018-08-01
• Series: Nuclear Materials and Energy
• Online Access: http://www.sciencedirect.com/science/article/pii/S2352179118300279
• ISSN: 2352-1791

Tungsten surface enrichment of EUROFER steel by 250 eV deuterium sputtering is in-situ measured using low energy He+ ion scattering spectroscopy. The samples are irradiated at various temperatures between 300 K and 800 K with a deuterium atom flux of 2 × 1018 m−2 s−1 and maximum fluence up to 1.1 × 1023 m−2. The measurements at room temperature show a clear increase of tungsten surface density, but already at 520 K the observed enrichment is only half as large. At a temperature of 800 K no tungsten surface enrichment is detectable. The obtained data yield an upper limit of 1.6 eV for the diffusion activation energy of tungsten in EUROFER. Keywords: Low energy ion scattering (LEIS), EUROFER, Plasma-surface interaction, Preferential sputtering, W diffusion in Fe, Diffusion activation energy