Journal
JOURNAL OF APPLIED PHYSICS
Volume 118, Issue 7, Pages -Publisher
AMER INST PHYSICS
DOI: 10.1063/1.4928407
Keywords
-
Categories
Funding
- Impuls- und Vernetzungsfond der Helmholtz-Gemeinschaft e.V.
Ask authors/readers for more resources
An effect of enhanced trapping of deuterium in tungsten at high flux was discovered. It was shown analytically and confirmed experimentally that the deuterium trapping in a presence of high density of defects in tungsten (W) depends on the ion energy and ion flux. Newly developed analytical model explains experimentally observed discrepancy of deuterium trapping at radiation-induced defects in tungsten at different ion fluxes that significantly improves a prediction of hydrogen isotope accumulation in different plasma devices, including ITER and DEMO. The developed model can be used for many system of hydrogen in a metal in both normal and extreme environments (high fluxes, elevated temperatures, neutron irradiation, etc.). This new model allows, for the first time, to validate density function theory (DFT) predictions of multiple occupation of a defect with deuterium against experimental data that bridge the gap in length and time scale between DFT calculations and experiments. By comparing first-principle calculations based on DFT and semi-empirical adsorption model, it was proved that the mechanism of hydrogen isotope trapping in a vacancy cluster is similar to a chemisorption on a surface. Binding energies of deuterium with different types of defects in W were defined. Moreover, the surface barrier of deuterium to be chemisorbed on a clean W surface was found to be less than 1 eV and kinetics of deuterium release is limited by de-trapping from defects rather than to be limited by surface effects. (C) 2015 AIP Publishing LLC.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available