Skip to Main content Skip to Navigation
Conference papers

Hydrogen accumulation around dislocation loops and edge dislocations: from atomistic to mesoscopic scales in BCC tungsten

Abstract : In a fusion tokamak, the plasma interacts with the metallic wall and the divertor. Hydrogen isotopes penetrate and diffuse into the material and interact with defects where they are trapped. Neutrons produced by the fusion reactions in the plasma are stopped in the material, creating defects, including vacancy and interstitial clusters, and dislocation loops. The trapping of hydrogen in vacancies has been extensively investigated. In our recent paper (De Backer et al 2017 Nucl. Fusion), we proposed a multi-scale model for H trapping and accumulation around interstitial defects, dislocation loops and dislocation lines. These defects create a long-range elastic field that attracts and may retain H atoms. A two-shell model with a short-range core region and a long-range elastic shell has been parameterized using a database of density functional theory (DFT) calculations. This model gives the number of H atoms forming the Cottrell atmosphere of a defect at finite temperature. In this paper, we present new DFT calculations of large dislocation loops decorated with up to 80 H, and explore our two-shell model in fusion relevant conditions. We conclude that large dislocation loops and edge dislocations can trap a significant number of hydrogen atoms in the core at temperatures up to 800 K, and also in the elastic field if the background hydrogen concentration is high.
Document type :
Conference papers
Complete list of metadata

https://hal.inrae.fr/hal-02737835
Contributor : Migration Prodinra Connect in order to contact the contributor
Submitted on : Tuesday, June 2, 2020 - 7:55:25 PM
Last modification on : Thursday, September 2, 2021 - 11:26:03 AM

Identifiers

Collections

Citation

Andrée de Backer, Daniel R. Mason, Christophe Domain, Duc Nguyen-Manh, Mihai-Cosmin Marinica, et al.. Hydrogen accumulation around dislocation loops and edge dislocations: from atomistic to mesoscopic scales in BCC tungsten. 16. International Conference on Plasma-Facing Materials and Components for Fusion Applications (PFMC-16), Forschungszentrum Jülich GmbH. DEU., May 2017, Neuss, Germany. ⟨10.1088/1402-4896/aa9400⟩. ⟨hal-02737835⟩

Share

Metrics

Record views

29