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Title: Preheating temperature effect on tritium retention in VPS-W

The W coating by Vacuum Plasma Spraying (VPS) technology is thought to be reasonable for most plasma facing components in future fusion reactors. In this paper the deuterium retention behavior for the Vacuum Plasma Spraying (VPS) tungsten (W) coating has been studied to demonstrate the tritium retention as a function of heating temperature. It has been found that two major deuterium desorption stages were observed at the temperature regions of 400 - 700 K (Stage 1) and 900 - 1100 K (Stage 2), considering that Stage 1 has been linked to the desorption of deuterium trapped by near surface and intrinsic defects, and Stage 2 has been related to the desorption of deuterium bound to impurities as C-D bonds. By heating the sample above 673 K, the major peak of C-1s shifted from C-O bond to C-C bond, where the retention of deuterium as Stage 2 has increased. Therefore it indicates that the hydrogen isotope retention was controlled by the amount of C-C bond in VPS, most of which was contaminated during the VPS coating process. The comparison of several samples (VPS-W with shading, VPS-W without shading and Polycrystalline W (PCW)) shows that the carbon impurity has a large affinitymore » with deuterium and makes stable trapping states compared to that with intrinsic defects and grain boundaries. However, most of them was reduced by heating at 1173 K. Therefore, heating treatment is quite important to get rid of carbon impurities and refrain higher tritium retention in VPS. (authors)« less
Authors:
; ; ; ;  [1] ; ; ;  [2] ;  [3] ; ;  [4] ;  [5]
  1. Graduate School of Science, Shizuoka University, Suruga-Ku, Shizuoka (Japan)
  2. Research Institute for Applied Mechanics, Kyushu University, Kasuga-city, Fukuoka (Japan)
  3. Hydrogen Isotope Research Center, University of Toyama, Toyama-city, Toyama (Japan)
  4. Institute of Advance Energy, Kyoto University, Gokasho, Uji, Kyoto (Japan)
  5. National Institute for Fusion Science, Toki-city, Gifu (Japan)
Publication Date:
OSTI Identifier:
22429764
Resource Type:
Journal Article
Resource Relation:
Journal Name: Fusion Science and Technology; Journal Volume: 67; Journal Issue: 3; Conference: TRITIUM 2013: 10. International Conference on Tritium Science and Technology, Nice Acropolis (France), 21-25 Oct 2013; Other Information: Country of input: France; 9 refs.
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; CARBON; COMPARATIVE EVALUATIONS; DESORPTION; DEUTERIUM; FIRST WALL; GRAIN BOUNDARIES; HEAT TREATMENTS; IMPURITIES; PLASMA; POLYCRYSTALS; SURFACE COATING; THERMONUCLEAR REACTORS; TRITIUM; TUNGSTEN