Relaxation volumes of microscopic and mesoscopic irradiation-induced defects in tungsten
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- Daniel R. Mason
- CCFE, UK Atomic Energy Authority, Culham Science Centre 1 , Oxfordshire OX14 3DB, United Kingdom
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- Duc Nguyen-Manh
- CCFE, UK Atomic Energy Authority, Culham Science Centre 1 , Oxfordshire OX14 3DB, United Kingdom
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- Mihai-Cosmin Marinica
- DEN-Service de Recherches de Metallurgie Physique, CEA, Universite Paris-Saclay 3 , F-91191 Gif-sur-Yvette, France
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- Rebecca Alexander
- Metallurgie Physique et Genie des Materiaux, UMET, CNRS, UMR 8207, Universite de Lille 4 , F-59000 Lille, France
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- Andrea E. Sand
- Department of Physics, University of Helsinki 5 , P.O. Box 43, FI-00014 Helsinki, Finland
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- Sergei L. Dudarev
- CCFE, UK Atomic Energy Authority, Culham Science Centre 1 , Oxfordshire OX14 3DB, United Kingdom
Description
<jats:p>The low-energy structures of irradiation-induced defects in materials have been studied extensively over several decades, as these determine the available modes by which a defect can diffuse or relax, and how the microstructure of an irradiated material evolves as a function of temperature and time. Consequently, many studies concern the relative energies of possible defect structures, and empirical potentials are commonly fitted to or evaluated with respect to these. But recently [S. L. Dudarev et al., Nucl. Fusion 58, 126002 (2018)], we have shown that other parameters of defects not directly related to defect energies, namely, their elastic dipole tensors and relaxation volumes, determine the stresses, strains, and swelling of reactor components under irradiation. These elastic properties of defects have received comparatively little attention. In this study, we compute relaxation volumes of irradiation-induced defects in tungsten using empirical potentials and compare to density functional theory results. Different empirical potentials give different results, but some clear potential-independent trends can be identified. We show that the relaxation volume of a small defect cluster can be predicted to within 10% from its point-defect count. For larger defect clusters, we provide empirical fits as a function of defect cluster size. We demonstrate that the relaxation volume associated with a single primary-damage cascade can be estimated from the primary knock-on atom energy. We conclude that while annihilation of defects invariably reduces the total relaxation volume of the cascade debris, there is still no conclusive verdict about whether coalescence of defects reduces or increases the total relaxation volume.</jats:p>
Journal
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- Journal of Applied Physics
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Journal of Applied Physics 126 (7), 075112-, 2019-08-19
AIP Publishing
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Details 詳細情報について
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- CRID
- 1360857596746381824
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- ISSN
- 10897550
- 00218979
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- Data Source
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- Crossref