Influence of exposure conditions on helium transport and bubble growth in tungsten
- Date: Jul 6, 2022
- Time: 03:30 PM - 04:30 PM (Local Time Germany)
- Speaker: Rémi Delaporte‑Mathurin
- CEA, France
- Location: Zoom Meeting Room 1
- Host: IPP
Helium diffusion, clustering and bubble nucleation and growth is modelled using the finite element method. The existing model from Faney et al. (Model Simul Mater Sci Eng 22:065010, 2018; Nucl Fusion 55:013014, 2015) is implemented with FEniCS and simplified in order to greatly reduce the number of equations. A parametric study is performed to investigate the influence of exposure conditions on helium inventory, bubbles density and size. Temperature is varied from 120 K to 1200 K and the implanted flux of 100 eV He is varied from 1017 m−2 s−1 to 5 × 1021 m−2 s−1. Bubble mean size increases as a power law of time whereas the bubble density reaches a maximum. The maximum He content in bubbles was approximately 4 × 108 He at 5 × 1021 m−2 s−1. After 1 h of exposure, the helium inventory varies from 5 × 1016 m−2 at low flux and high temperature to 1025 m−2 at high flux and low temperature. The bubbles inventory varies from 5 × 1012 bubbles m−2 to 2 × 1019 bubbles m−2. Comparison with experimental measurements is performed. The bubble density simulated by the model is in quantitative agreement with experiments.