Temperature dependence of underdense nanostructure formation in tungsten under helium irradiation

JOURNAL OF NUCLEAR MATERIALS

卷:490

Article

Valles, G.¹  Martin-Bragado, I.²  Nordlund, K.^3,4  Lasa, A.^3,5  Bjorkas, C.³  Safi, E.³  Perlado, J. M.¹  Rivera, A.¹ 

[1] Univ Politecn Madrid, Inst Fus Nucl, C Jose Gutierrez Abascal 2, E-28006 Madrid, Spain

[2] Univ Catolica Murcia, UCAM, Campus Jeronimos, Murcia 30107, Spain

[3] Univ Helsinki, Dept Phys, POB 43, FI-00014 Helsinki, Finland

[4] Natl Res Nucl Univ MEPhI, Moscow 115409, Russia

[5] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

关键词: Tungsten;    Helium irradiation;    Fuzz nanostructures;    OKMC simulations;    Temperature;   

DOI  :  10.1016/j.jnucmat.2017.04.021

来源: Elsevier

【 摘 要 】

Recently, tungsten has been found to form a highly underdense nanostructured morphology (W fuzz) when bombarded by an intense flux of He ions, but only in the temperature window 900-2000 K. Using object kinetic Monte Carlo simulations (pseudo-3D simulations) parameterized from first principles, we show that this temperature dependence can be understood based on He and point defect clustering, cluster growth, and detrapping reactions. At low temperatures (<900 K), fuzz does not grow because almost all He is trapped in very small He-vacancy clusters. At high temperatures (>2300 K), all He is detrapped from clusters, preventing the formation of the large clusters that lead to fuzz growth in the intermediate temperature range. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

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