About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Transmutation Effects in Fusion Reactor Materials: Critical Challenges & Path Forward
|
| Presentation Title |
Ab Initio and Classical Molecular Dynamics Study of Re Transport in W |
| Author(s) |
Osetsky Yury, German Samolyuk |
| On-Site Speaker (Planned) |
Osetsky Yury |
| Abstract Scope |
Experiments observed intensive Re clustering and precipitate formation under irradiation conditions. The current assumption is that Re is transported by a non-dissociative low energy interstitial-mediated mechanism that is incorporated into kinetic Monte Carlo modeling parameterized using defect energies derived by ab initio calculations. Here we demonstrate that the fast diffusion path, combining several configurations with similar energies and low-energy transition states between them, may not be realized under the truly dynamic conditions necessary for thermally activated diffusion. Using ab initio molecular dynamics modeling (AIMD), we determined that Re transport is very slow and occurs via a dissociative mechanism. Larger scale classical MD estimated diffusion coefficients and demonstrated that the activation energy for Re transport is controlled by the dissociation energy of the Re-contained interstitial. The overall diffusivity by interstitial migration in W-Re system is decreased by two orders in magnitude compared to pure W. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Nuclear Materials, |