Revealing the role of oxygen on the defect evolution of electron-irradiated tungsten: A combined experimental and simulation study - CEA - Commissariat à l’énergie atomique et aux énergies alternatives
Article Dans Une Revue Journal of Nuclear Materials Année : 2024

Revealing the role of oxygen on the defect evolution of electron-irradiated tungsten: A combined experimental and simulation study

Résumé

The evolution of Frenkel pairs has been studied experimentally and theoretically in tungsten, a Body-Centered Cubic metal. We used positron annihilation spectroscopy to characterize vacancy defects induced by electron irradiation in two sets of polycrystalline tungsten samples at room temperature. Doppler Broadening spectrometry showed that some positrons are trapped at pure single vacancies with a lower concentration than expected. At the same time, positron annihilation lifetime spectroscopy revealed that positrons are annihilated in unexpected states with a lifetime 1.44-1.64 times shorter than that of single vacancy (200 ps), namely unidentified (X) defects. Secondary ions mass spectrometry detected a significant concentration of oxygen in these samples, of the same order of magnitude as electron-induced single vacancy. In addition, Cluster dynamics simulated defect behaviors under experimental conditions, and Two-component density functional theory were used to calculate defect annihilation characteristics that are difficult to obtain in experiments. Finally, by combining the theoretical data, we simulated the positron signals and compared them with the experimental data. This enabled us to elucidate the interactions between oxygen and Frenkel pairs. The X defects were identified as oxygen-vacancy complexes formed during irradiation, as oxygen is mobile in tungsten at room temperature, and can be trapped in a vacancy, while its binding to self-ion atoms leads to their immobilization thus reducing defect recombination. Therefore, we expect oxygen to play an important role in the evolution of tungsten microstructure under irradiation.

Domaines

Matériaux
Fichier principal
Vignette du fichier
postprint.pdf (2.05 Mo) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)

Dates et versions

cea-04682709 , version 1 (30-08-2024)

Identifiants

Citer

Zhiwei Hu, Qigui Yang, François Jomard, Pierre Desgardin, Cécile Genevois, et al.. Revealing the role of oxygen on the defect evolution of electron-irradiated tungsten: A combined experimental and simulation study. Journal of Nuclear Materials, 2024, 602, pp.155353. ⟨10.1016/j.jnucmat.2024.155353⟩. ⟨cea-04682709⟩
37 Consultations
10 Téléchargements

Altmetric

Partager

More