Atomistic simulations of deuterium irradiation on iron-based alloys in future fusion reactors

Journal Article · 14 October 2016 · Nuclear Materials and Energy

DOI: https://doi.org/10.1016/j.nme.2016.08.021 · OSTI ID:1346656

Safi, E. ^[1]; Polvi, J.  ^[1]; Lasa, A.  ^[2]; Nordlund, K. ^[1]

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1. Univ. of Helsinki (Finland). Association EURATOM-Tekes
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Iron-based alloys are now being considered as plasma-facing materials for the first wall of future fusion reactors. Therefore, the iron (Fe) and carbon (C) erosion will play a key role in predicting the life-time and viability of reactors with steel walls. In this work, the surface erosion and morphology changes due to deuterium (D) irradiation in pure Fe, Fe with 1% C impurity and the cementite, are studied using molecular dynamics (MD) simulations, varying surface temperature and impact energy. The sputtering yields for both Fe and C were found to increase with incoming energy. In iron carbide, C sputtering was preferential to Fe and the deuterium was mainly trapped as D₂ in bubbles, while mostly atomic D was present in Fe and Fe–1%C. The sputtering yields obtained from MD were compared to SDTrimSP yields. At lower impact energies, the sputtering mechanism was of both physical and chemical origin, while at higher energies (>100 eV) the physical sputtering dominated.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1346656
• Journal Information: Nuclear Materials and Energy, Vol. 9; ISSN 2352-1791
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English