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Title: Nucleation and growth of tungsten nanotendrils grown under divertor-like conditions

Abstract

Tungsten is the primary candidate for plasma-facing materials in the critical regions of a magnetic fusion energy (MFE) device, such as a tokamak. However, tungsten (and many other metals) grow copious nanotendril "fuzz" when exposed to fusion-relevant He-bearing plasmas, and the impact of this fuzz on reactor operation is still unknown. Further, the mechanism of fuzz growth is also poorly understood at present. In order to experimentally probe the growth mechanisms, we developed a new sample preparation technique to examine the interface of individual nanotendril roots with the substrate (substrate/tendril interface) using electron microscopy and measured the grain boundary character distributions (GBCDs) of substrate/tendril interfaces, the GBs within individual tendrils (tendril/tendril interfaces), and GBs within the substrate (substrate/substrate interfaces). We find the substrate/tendril and tendril/tendril GBCDs are essentially indistinguishable, but very different from the substrate/substrate GBCDs, which implies that tendril growth periodically forms new GBs at the substrate/tendril interface, and these GBs are pushed upward to become tendril/tendril interfaces within the fuzz mat. These results will help guide future computational modelling studies to elucidate the details of the growth mechanisms.

Authors:
ORCiD logo [1];  [2];  [2]; ORCiD logo [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Univ. of California, San Diego, CA (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1777822
Alternate Identifier(s):
OSTI ID: 1548076
Grant/Contract Number:  
AC05-00OR22725; FG02-07ER54912
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 509; Journal Issue: 0; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS

Citation Formats

Wang, Kun, Doerner, R. P., Baldwin, Matthew J., and Parish, Chad. Nucleation and growth of tungsten nanotendrils grown under divertor-like conditions. United States: N. p., 2018. Web. doi:10.1016/j.jnucmat.2018.07.043.
Wang, Kun, Doerner, R. P., Baldwin, Matthew J., & Parish, Chad. Nucleation and growth of tungsten nanotendrils grown under divertor-like conditions. United States. https://doi.org/10.1016/j.jnucmat.2018.07.043
Wang, Kun, Doerner, R. P., Baldwin, Matthew J., and Parish, Chad. Mon . "Nucleation and growth of tungsten nanotendrils grown under divertor-like conditions". United States. https://doi.org/10.1016/j.jnucmat.2018.07.043. https://www.osti.gov/servlets/purl/1777822.
@article{osti_1777822,
title = {Nucleation and growth of tungsten nanotendrils grown under divertor-like conditions},
author = {Wang, Kun and Doerner, R. P. and Baldwin, Matthew J. and Parish, Chad},
abstractNote = {Tungsten is the primary candidate for plasma-facing materials in the critical regions of a magnetic fusion energy (MFE) device, such as a tokamak. However, tungsten (and many other metals) grow copious nanotendril "fuzz" when exposed to fusion-relevant He-bearing plasmas, and the impact of this fuzz on reactor operation is still unknown. Further, the mechanism of fuzz growth is also poorly understood at present. In order to experimentally probe the growth mechanisms, we developed a new sample preparation technique to examine the interface of individual nanotendril roots with the substrate (substrate/tendril interface) using electron microscopy and measured the grain boundary character distributions (GBCDs) of substrate/tendril interfaces, the GBs within individual tendrils (tendril/tendril interfaces), and GBs within the substrate (substrate/substrate interfaces). We find the substrate/tendril and tendril/tendril GBCDs are essentially indistinguishable, but very different from the substrate/substrate GBCDs, which implies that tendril growth periodically forms new GBs at the substrate/tendril interface, and these GBs are pushed upward to become tendril/tendril interfaces within the fuzz mat. These results will help guide future computational modelling studies to elucidate the details of the growth mechanisms.},
doi = {10.1016/j.jnucmat.2018.07.043},
journal = {Journal of Nuclear Materials},
number = 0,
volume = 509,
place = {United States},
year = {Mon Jul 23 00:00:00 EDT 2018},
month = {Mon Jul 23 00:00:00 EDT 2018}
}

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Cited by: 11 works
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Works referencing / citing this record:

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