Bulletin of the American Physical Society
63rd Annual Meeting of the APS Division of Plasma Physics
Volume 66, Number 13
Monday–Friday, November 8–12, 2021; Pittsburgh, PA
Session PO08: MFE: Plasma-Material Interactions
2:00 PM–5:00 PM,
Wednesday, November 10, 2021
Room: Rooms 317-318
Chair: Tyler Abrams, General Atomics - San Diego
Abstract: PO08.00014 : Effect of Thermal Cycling on Morphology Changes and Deuterium Retention in Helium Exposed Tungsten*
4:36 PM–4:48 PM
Presenter:
Mykola Ialovega
(CEA Cadarache, Univ. of Wisconsin-Madison)
Authors:
Mykola Ialovega
(CEA Cadarache, Univ. of Wisconsin-Madison)
Elodie Bernard
(CEA Cadarache)
Celine Martin
(Univ. Aix-Marseille)
Regis Bisson
(Univ. Aix-Marseille)
Christian Grisolia
(CEA Cadarache)
Thierry Angot
(Univ. Aix-Marseille)
In this work, the shape and density evolution of helium bubbles in W is investigated for temperature and He flux conditions relevant to those expected in ITER. Sets of thermal cycling experiments up to 1350 K with a temperature ramp of 1 K/s followed by an extensive surface and near-surface characterization of He-exposed W revealed shaping of surface holes and helium bubbles and their removal in the 5 nm subsurface layer. Cross-sectional observations of the bubbles under different zone axes indicate that the shape of the bubbles is most likely rhombic dodecahedron consisting of 12 congruent rhombic faces of (110) orientation delimited by <110> edges. This is in agreement with theoretical considerations since the shape of the bubbles is determined by the surface energy minima, thus the voids in the W bcc metal should form faces of (110) orientation. Furthermore, the observed structural changes in He-exposed W correlate with a modification of deuterium release mechanisms [2].
Electron energy loss spectroscopy measurements confirmed the presence of He in the bubbles even after annealing up to 1350 K. In conclusion, our work gives additional knowledge on the fundamental physics of the gas-metal interactions and confirms the importance to pursue investigations on the effects of high fluence He exposure on W material properties for its successful application as a PFM in the next generation fusion devices.
*The project received funding from the A*Midex Initiative, "Investissements d'Avenir'' programme and from the ANR under grant ANR-18-CE05-12. The presentation of this work is supported by the USDoE ARPA-E.
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700