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Thermal Diffusivity and Thermal Conductivity of Carbon Materials for Tokamak Limiters

  • E. P. Roth
  • M. Moss

Abstract

A plasma limiter is used to control the plasma size in Tokamak fusion research devices and serves as one of the main areas of plasma wall interaction. Wall temperatures can reach as high as 3000 K resulting in significant sputtering and wall erosion. Graphite and graphite composites have been chosen as the materials which best meet the requirements of this severe environment. The thermal conductivities of these materials are critical to the modeling of the thermophysical response of the limiters during operation. The thermal conductivities of several candidate materials were measured. Three categories of materials were investigated in this study: pyrolytic graphite and annealed pyrolytic graphite; carbon/carbon fiber composites composed of two- directionally woven fibers with a graphitized pitch matrix; carbon/carbon fiber composites with a four-directional carbon fiber weave. The thermal conductivities of the carbon/carbon fiber composites were determined as a function of fiber orientation. Conductivities were measured using both the laser flash diffusivity technique and the thermal comparative method. The advantages and disadvantages of each of these methods will be discussed and the data compared.

Keywords

Thermal Conductivity Fiber Composite Pyrolytic Graphite Sandia National Laboratory Radial Heat Flow 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    R.W. Conn, “Relation of Surface Interactions to First-Wall and In-Vessel (IVC) Design and Materials Performance in Fusion Devices”, J. Nucl. Mater.. 103 and 104. 7 (1981).CrossRefGoogle Scholar
  2. 2.
    W.J. Parker, R.J. Jenkins, et al. “A Flash Method of Determining Thermal Diffusivity, Heat Capacity, and Thermal Conductivity”, U.S. Navy Technical Report USNRDL-TR-424, May, 1960.Google Scholar
  3. 3.
    J.A. Koski, “Improved Data Reduction Methods for Laser Pulse Diffusivity Determination with the use of Minicomputers”, Proceedings of the Eighth Symposium on Thermophysical Properties, Vol. II: Thermophysical Properties of Solids and of Selected Fluids for Energy Technology, ASME, New York, (1982), pp. 94 - 103.Google Scholar
  4. 4.
    D.L. Balageas and A.M. Luc, “Transient Thermal Behavior of Directional Reinforced Composites: Applicability Limits of Homogeneous Property Model”, AIAA J., 24, 109 (1986).CrossRefGoogle Scholar
  5. 5.
    A. Whittaker, R. Taylor, and H. Tawil, “Thermal Diffusivity of Some Fine-Weave Carbon/Carbon-Fiber Composites”, High Temperatures-High Pressures. 17, 225 (1985).Google Scholar
  6. 6.
    R.L. Shoemaker, “Limitations of the Pulse Diffusivity Method as Applied to Composite Materials”, High Temperatures-High Pressures. 18, 645 (1986).Google Scholar
  7. 7.
    Infrared detector from Properties Research Laboratory, Box 2224, East Lafayette, Indiana 47906.Google Scholar
  8. 8.
    Reference to a particular product or company implies neither a recommendation nor an endorsement by Sandia National Laboratories, nor a lack of suitable substitutes.Google Scholar
  9. 9.
    Hewlett-Packard Co., Cupertino, CA 95014.Google Scholar
  10. 10.
    E. Fitzer, “Results of the Cooperative Measurements on Heat Transport Properties up to 2800 K”, AGARD-R-606, Technical Editing and Reproduction Ltd., Harford House, 7-9 Charlotte St., London WIP 1H, 1973.Google Scholar
  11. 11.
    The model TCFCM comparative thermal conductivity instrument is manufactured by Dynatech R/D Co., Cambridge, MA. The Colora thermoconductometer is manufactured by Colora Messtechnik GMBH, Lorch/Württemberg, FRG, and is sold by Dynatech.Google Scholar
  12. 12.
    M. Moss, J.A. Koski, and G.M. Haseman, “Measurement of Thermal Conductivity by the Comparative Method”, Report No. SAND82-0109, Sandia National Laboratories, Albuquerque, NM (1982).Google Scholar
  13. 13.
    J.N. Sweet, M. Moss, and C.E. Sisson, “The Use of Numerical Heat Transfer Techniques to Analyze Thermal Comparator Conductivity Measurements”, Thermal Conductivity 18. T. Ashworth and D.R. Smith eds., Plenum, New York (1985).Google Scholar
  14. 14.
    J.N. Sweet, E.P. Roth, M. Moss, G.M. Haseman, and A.J. Anaya, “Comparative Thermal Conductivity Measurements at Sandia National Laboratories”, Report No. SAND86-0840, Sandia National Laboratories, Albuquerque, NM (1986).Google Scholar
  15. 15.
    J.N. Sweet, “Establishments of Accuracy Limits and Standards for Comparative Thermal Conductivity Measurements”, Int. J. Thermophysics. 7, 743 (1986).CrossRefGoogle Scholar
  16. 16.
    Carpenter Technology Corp., Reading, PA.Google Scholar
  17. 17.
    L.C. Beavis and M. Moss, “Thermally Conductive Silicone Based Materials for Attaching Concentrator Solar Cells to Heat Sinks”, Symposium Series, No. 245, Vol. 81, Proc. 23rd AIChE/ASME National Heat Transfer Conf., Denver, CO, 1985 Amer. Inst. Chem. Eng., New York (1985).Google Scholar
  18. 18.
    Perkin-Elmer Corp., Norwalk, CT.Google Scholar
  19. 19.
    A.T.D. Butland and R.J. Madison, J. Nucl. Mater.. 49, 45 (1973).CrossRefGoogle Scholar
  20. 20.
    B.F. Goodrich, Aerospace and Defense Division, Super-Temp Operations, 11120 South Norwalk Blvd., Santa Fe Spring, CA 90670.Google Scholar
  21. 21.
    Pfizer, Inc., 640 N. 13th St., Easton, PA 18042-1497.Google Scholar
  22. 22.
    Carbone Lorraine, Carbone USA Corp., 400 Myrtle Ave., Boonton, NJ 87005.Google Scholar
  23. 23.
    SIGRI GmbH, Post Box 11 60, 8901 Meitingen, FRG.Google Scholar
  24. 24.
    Schunk Kohlenstofftechnik GmbH, Post Box 64 20, 6300 Geissen, FRG.Google Scholar
  25. 25.
    Fiber Materials Inc., Biddeford Industrial Park, Biddeford, ME 04005.Google Scholar
  26. 26.
    J.B. Smith, R.L. Burns, and L.L. Lander, “Low Cost/High Performance Carbon-Carbon Nozzles”, Tech. Report: RK-CK-83-2 for Propulsion Directorate, U.S. Army Missile Laboratory, Redstone Arsenal, AL 35898 (1982).Google Scholar
  27. 27.
    B.T. Kelly, “The Thermal Conductivity of Graphite”, Chem. Phys. Carbon. 5, 119 (1969).Google Scholar
  28. 28.
    R. Taylor, “The Thermal Conductivity of Pyrolytic Graphite”, Phil. Mag., 13, 157 (1966).CrossRefGoogle Scholar
  29. 29.
    M. Moss and G. Haseman, “A Proposed Model for the Thermal Conductivity of Dry and Water-Saturated Tuff”, Materials Research Society Symp. Proc. 26, Elsevier, New York (1984), p. 967.Google Scholar

Copyright information

© Purdue Research Foundation 1989

Authors and Affiliations

  • E. P. Roth
    • 1
  • M. Moss
    • 1
  1. 1.Thermophysical Properties DivisionSandia National LaboratoriesAlbuquerqueUSA

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