Dynamic measurement of the helium concentration of evolving tungsten nanostructures using Elastic Recoil Detection during plasma exposure
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Whyte_Dynamic measurement.pdf
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Author(s)
Woller, Kevin Benjamin
Whyte, Dennis G
Wright, Graham
Date Issued
December 2014
Journal
Journal of Nuclear Materials
Publisher
Elsevier
Citation
Woller, K.B. et al. “Dynamic Measurement of the Helium Concentration of Evolving Tungsten Nanostructures Using Elastic Recoil Detection During Plasma Exposure.” Journal of Nuclear Materials 463 (August 2015): 289–293 © 2014 Elsevier B.V.
Version
Author's final manuscript
Abstract
Helium (He) concentration depth profiles of evolving tungsten (W) nanostructures have been measured for the first time using in situ Elastic Recoil Detection (ERD) throughout plasma irradiation. Exposures resulting in fuzzy and non-fuzzy surfaces were analyzed in order to illuminate the role of He during the development of these surface morphologies. ERD was performed on samples with surface temperatures from Ts = 530–1100 K and irradiated by He flux densities of ΓHe ∼ 10²⁰–10²² m⁻² s⁻¹. He concentration profiles in samples that developed either non-fuzzy or fuzzy surfaces are uniformly shaped with concentrations of 1.5–7 at.%, which is presumed to be too low for pressure driven growth models. Therefore, surface morphology changes are not perpetuated by continuous bubble bursting deformation. Also, a threshold in He flux density above 1020 m⁻²s⁻¹ is suggested by using in situ ERD to monitor the depth profile evolution of the He-rich layer while changing the flux during exposure.
MIT Department
Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
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DOI of Published Version
https://doi.org/10.1016/j.jnucmat.2014.11.126
