Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5454006 | Journal of Nuclear Materials | 2017 | 7 Pages |
Abstract
Currently, tungsten remains the best candidate for plasma-facing components (PFCs) for future fusion devices because of its high melting point, low erosion, and strong mechanical properties. However, continued investigation has shown tungsten to undergo severe morphology changes under fusion-like conditions. These results motivate the study of innovative PFC materials which are resistant to surface morphology evolution. The goal of this work is to examine tungsten-tantalum (W-Ta) alloys, a potential PFC material, and their response to low energy helium ion irradiation. Specifically, W-Ta samples are exposed to 100Â eV helium irradiations with a flux of 1.15Â ÃÂ 1021 ions mâ2 sâ1, at 873Â K, 1023Â K, and 1173Â K for 1Â h duration. Scanning electron microscopy (SEM) reveals significant changes in surface deterioration due to helium ion irradiation as a function of both temperature and tantalum concentration in W-Ta samples. X-Ray Diffraction (XRD) studies show a slight lattice parameter expansion in W-Ta alloy samples compared to pure W samples. The observed lattice parameter expansion in W-Ta alloy samples (proportional to increasing Ta wt.% concentrations) reflect significant differences observed in the evolution of surface morphology, i.e., fuzz development processes for both increasing Ta wt.% concentration and target temperature. These results suggest a correlation between the observed morphology differences and the induced crystal structure change caused by the presence of tantalum. Shifts in the XRD peaks before and after 100Â eV helium irradiation with a flux of 1.15Â ÃÂ 1021 ions mâ2 sâ1, 1023Â K, for 1Â h showed a significant difference in the magnitude of the shift. This has suggested a possible link between the atomic spacing of the material and the accumulated damage. Ongoing research is needed on W-Ta alloys and other innovative materials for their application as irradiation resistant materials in future fusion or irradiation environments.
Related Topics
Physical Sciences and Engineering
Energy
Nuclear Energy and Engineering
Authors
S. Gonderman, J.K. Tripathi, T.J. Novakowski, T. Sizyuk, A. Hassanein,