Interaction of deuterium plasma with sputter-deposited tungsten nitride films
L. Gao, W. Jacob, G. Meisl, T. Schwarz-Selinger, T. Höschen, U. von Toussaint, T. Dürbeck
Abstract
Abstract Magnetron-sputtered tungsten nitride (WN x ) films were used as a model system to study the behaviour of re-deposited WN x layers which could form in fusion devices with tungsten (W) wall during nitrogen seeding. The interaction of such WN x layers with deuterium (D) plasmas was investigated in dedicated laboratory experiments. D retention and N removal due to D plasma exposure (D flux: 9.9 × 10 19 D m −2 s −1 , ion energy 215 eV) at different temperatures were measured with ion beam analysis (IBA). Low-energy argon sputtering followed by IBA was applied to resolve the D distribution in the top-most surface of WN x with significantly improved depth resolution compared with the standard D depth profiling method by nuclear reaction analysis. Experimentally determined thicknesses for the penetration of D in WN x were compared with the penetration depth for D calculated in SDTrimSP simulations. Results show that D is only retained within the ion penetration range for samples exposed at 300 K. In contrast to the 300 K case, D diffuses beyond the implantation depth in a sample exposed at 600 K. However, the D penetration depth is much lower than in pure W at comparable conditions. The total amount of retained D in WN x at 600 K is by 50% lower than for implantation at 300 K with the same D fluence. Nitrogen is removed only within the D ion range.
BibTeX
@article{Gao_2015,
title={Interaction of deuterium plasma with sputter-deposited tungsten nitride films},
volume={56},
ISSN={1741-4326},
url={http://dx.doi.org/10.1088/0029-5515/56/1/016004},
DOI={10.1088/0029-5515/56/1/016004},
number={1},
journal={Nuclear Fusion},
publisher={IOP Publishing},
author={Gao, L. and Jacob, W. and Meisl, G. and Schwarz-Selinger, T. and Höschen, T. and von Toussaint, U. and Dürbeck, T.},
year={2015},
month=nov,
pages={016004} }