skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on May 23, 2020

Title: Development and Performance of Tungsten-Coated Graphitic Foam for Plasma-Facing Components

Abstract

High-density graphitic foam is an ideal low-Z plasma-facing material for deuterium-deuterium plasma experiments where tritium codeposition is not an issue. However, like all carbon, graphitic foam suffers from a precipitous drop in thermal conductivity at high temperatures, >600°C. To mitigate these problems, functionally graded layers of tungsten can be deposited to a thickness of 2 to 4 mm onto the plasma side of the foam using chemical vapor deposition. The graphitic foam then acts as a high-conductivity heat sink at temperatures below 600°C for the thin high-Z armor coating. The overall component weighs 18 times less than a comparable volume of tungsten and lacks the coefficient of thermal expansion joining issues between the CuCrZr tubing and the tungsten. This paper discusses the coating development and characterization and presents the results of recent plasma exposures in W7-X. It also reports on computational fluid dynamics heat transfer modeling and preparations for high heat flux testing of mock-ups. This hybrid plasma-facing component (PFC) consisting of innovative engineered materials may be a cost-effective, actively cooled solution for the divertors and other PFCs in long-pulse machines like W7-X and WEST.

Authors:
ORCiD logo [1]; ORCiD logo [2]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1];  [3];  [2];  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Forschungszentrum Julich, Julich (Germany)
  3. Missouri Univ. of Science and Technology, Rolla, MO (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) (SC-24)
OSTI Identifier:
1559710
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
Fusion Science and Technology
Additional Journal Information:
Journal Volume: 75; Journal Issue: 6; Journal ID: ISSN 1536-1055
Publisher:
American Nuclear Society
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Graphitic foam; tungsten; coating; divertor; plasma-facing component

Citation Formats

Youchison, Dennis L., Coenen, J. W., Gray, Travis K., Lumsdaine, Arnold, Klett, James W., Jolly, Brian C., Gehrig, Monica, Brezinsek, S., and Rasinski, M. Development and Performance of Tungsten-Coated Graphitic Foam for Plasma-Facing Components. United States: N. p., 2019. Web. doi:10.1080/15361055.2019.1607706.
Youchison, Dennis L., Coenen, J. W., Gray, Travis K., Lumsdaine, Arnold, Klett, James W., Jolly, Brian C., Gehrig, Monica, Brezinsek, S., & Rasinski, M. Development and Performance of Tungsten-Coated Graphitic Foam for Plasma-Facing Components. United States. doi:10.1080/15361055.2019.1607706.
Youchison, Dennis L., Coenen, J. W., Gray, Travis K., Lumsdaine, Arnold, Klett, James W., Jolly, Brian C., Gehrig, Monica, Brezinsek, S., and Rasinski, M. Thu . "Development and Performance of Tungsten-Coated Graphitic Foam for Plasma-Facing Components". United States. doi:10.1080/15361055.2019.1607706.
@article{osti_1559710,
title = {Development and Performance of Tungsten-Coated Graphitic Foam for Plasma-Facing Components},
author = {Youchison, Dennis L. and Coenen, J. W. and Gray, Travis K. and Lumsdaine, Arnold and Klett, James W. and Jolly, Brian C. and Gehrig, Monica and Brezinsek, S. and Rasinski, M.},
abstractNote = {High-density graphitic foam is an ideal low-Z plasma-facing material for deuterium-deuterium plasma experiments where tritium codeposition is not an issue. However, like all carbon, graphitic foam suffers from a precipitous drop in thermal conductivity at high temperatures, >600°C. To mitigate these problems, functionally graded layers of tungsten can be deposited to a thickness of 2 to 4 mm onto the plasma side of the foam using chemical vapor deposition. The graphitic foam then acts as a high-conductivity heat sink at temperatures below 600°C for the thin high-Z armor coating. The overall component weighs 18 times less than a comparable volume of tungsten and lacks the coefficient of thermal expansion joining issues between the CuCrZr tubing and the tungsten. This paper discusses the coating development and characterization and presents the results of recent plasma exposures in W7-X. It also reports on computational fluid dynamics heat transfer modeling and preparations for high heat flux testing of mock-ups. This hybrid plasma-facing component (PFC) consisting of innovative engineered materials may be a cost-effective, actively cooled solution for the divertors and other PFCs in long-pulse machines like W7-X and WEST.},
doi = {10.1080/15361055.2019.1607706},
journal = {Fusion Science and Technology},
number = 6,
volume = 75,
place = {United States},
year = {2019},
month = {5}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on May 23, 2020
Publisher's Version of Record

Save / Share:

Works referenced in this record:

Structural and mechanical characterization of graphite foam/phase change material composites
journal, August 2014


Chemical vapor deposition of Mo tubes for fuel cladding applications
journal, March 2018


High heat flux facility GLADIS:
journal, August 2007


Integrated plasma facing component calorimetry for measurement of shot integrated deposited energy in the NSTX-U
journal, October 2018

  • Gray, T. K.; Allen, N.; Reinke, M. L.
  • Review of Scientific Instruments, Vol. 89, Issue 10
  • DOI: 10.1063/1.5039337

Engineering Challenges in W7-X: Lessons Learned and Status for the Second Operation Phase
journal, May 2018

  • Bosch, H. -S.; Andreeva, T.; Brakel, R.
  • IEEE Transactions on Plasma Science, Vol. 46, Issue 5
  • DOI: 10.1109/TPS.2018.2818934

High heat-flux response of high-conductivity graphitic foam monoblocks
journal, September 2019


The role of structure on the thermal properties of graphitic foams
journal, June 2004


A multi-purpose manipulator system for W7-X as user facility for plasma edge investigation
journal, November 2017


Plasma exposures of a high-conductivity graphitic foam for plasma facing components
journal, December 2018


Prototyping phase of the high heat flux scraper element of Wendelstein 7-X
journal, November 2016