Basic Properties of Fusion Edge Plasmas and Role of Atomic and Molecular Processes

  • R. K. Janev

Abstract

The self-sustained thermonuclear burn of a deuterium-tritium (D-T) plasma in a fusion reactor relies on maintaining certain stringent conditions imposed on the plasma parameters (temperature and density), plasma energy confinement time, and power generating and loss processes. The plasma burn condition requires that the power density of fusion-born alpha particles exceeds the sum of the densities of all radiative and thermal power losses. While the thermal power losses are determined by collective plasma transport phenomena, the radiation losses (such as bremsstrahlung and line radiation) are determined by collisional and radiative atomic processes. Nonhydrogenic species (impurities) present in the plasma may substantially increase the radiation losses and, above certain critical amounts (e.g., 1% of plasma density for Fe and 0.1% of plasma density for W), may extinguish the burn. The fusion-born alpha particles carry about one-fifth of the total fusion power generated by D-T thermonuclear reactions, and only a small part of it is used to sustain the thermonuclear burn or is lost by bremsstrahlung radiation. The remaining power, as well as the alpha particles themselves, have to be removed from the burning reactor zone in order to avoid plasma overheating and poisoning. The accumulation of alpha particles in the reacting zone (He ash) dilutes the thermonuclear fuel, degrades the burning conditions, and, above certain levels, may extinguish the plasma burn. Under steady-state conditions, the alpha particles have to be removed from the reactor at a rate equal to that of their production.

Keywords

Plasma Edge Divertor Plate Limiter Configuration Magnetic Flux Surface Divertor Plasma 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    P. C. Stangeby and G. M. McCracken, Nucl. Fusion 30, 1225 (1990).CrossRefGoogle Scholar
  2. 2.
    D. E. Post and K. Lackner, in Physics of Plasma-Wall Interactions in Controlled Fusion (D. E. Post and R. Behrisch, eds.), Plenum, New York (1984), p. 627.Google Scholar
  3. 3.
    M. F. A. Harrison, E. S. Hotson, J. G. Morgan, and G. P. Maddison, Plasma Edge Physics for NET/1NTOR, Report CLM-P761, United Kingdom Atomic Energy Authority, Culham Laboratory, Abingdon, U.K., 1985.Google Scholar
  4. 4.
    M. F. A. Harrison, in Atomic Processes in Electron-Ion and Ion-Ion Collisions (F. Brouillard, ed.), Plenum, New York (1986), p. 421.CrossRefGoogle Scholar
  5. 5.
    M. F. A. Harrison, in Atomic and Plasma-Material Interaction Processes in Controlled Thermonuclear Fusion (R. K. Janev and H. W. Drawin, eds.), Elsevier, Amsterdam (1993), p. 285.Google Scholar
  6. 6.
    R. K. Janev, M. F. A. Harrison, and H. W. Drawin, Nucl. Fusion 29, 109 (1989).CrossRefGoogle Scholar
  7. 7.
    R. K. Janev, Comments At. Mol. Phys. 26, 83 (1991).Google Scholar
  8. 8.
    K. Miyamoto, Plasma Physics for Nuclear Fusion, MIT Press, Cambridge, Massachusetts (1976).Google Scholar
  9. 9.
    R. A. Hulse, Nucl. Technol./Fusion 3, 259 (1983).Google Scholar
  10. 10.
    International Tokamak Reactor, Phase IIA, Part 3, International Atomic Energy Agency, Vienna, 1988.Google Scholar
  11. 11.
    International Thermonuclear Experimental Reactor Concept Definition, Vol. 2, IAEA Documentation Series, No. 3, International Atomic Energy Agency, Vienna, 1989.Google Scholar
  12. 12.
    M. L. Watkins and P. H. Rebut, in Controlled Fusion and Plasma Heating (Proceedings of the 19th European Conference on Plasma Physics and Controlled Fusion, Innsbruck, 1992), Vol. 16C, Part II, European Physical Society, Geneva, (1992), p. 731.Google Scholar
  13. 13.
    J. Roth, in Physics of Plasma-Wall Interactions in Controlled Fusion (D. Post and R. Behrisch, eds.), Plenum, New York (1984), pp. 351 and 389.Google Scholar
  14. 14.
    S.I. Braginskii, inReviews of Plasma Physics, Vol. 1 (M. A. Leontovich, ed.), Consultants Bureau, New York (1965), p. 205.Google Scholar
  15. 15.
    E. L. Vold, Contrib. Plasma Phys. 32, 404 (1992).ADSCrossRefGoogle Scholar
  16. 16.
    D. Reiter, in Atomic and Plasma-Material Interaction Processes in Controlled Thermonuclear Fusion (R. K. Janev and H. W. Drawin, eds.), Elsevier, Amsterdam (1993).Google Scholar
  17. 17.
    D. Reiter, J. Nucl. Mater. 196–198, 80 (1992).Google Scholar
  18. 18.
    K. Borrass and G. Janeschitz, Nucl. Fusion 34, 1203 (1994).ADSCrossRefGoogle Scholar
  19. 19.
    H. Tawara and R. A. Phaneuf, Comments At. Mol. Phys. 21, 177 (1988).Google Scholar
  20. 20.
    R. A. Phaneuf and R. K. Janev, in Atomic and Plasma-Material Interaction Processes in Controlled Thermonuclear Fusion (R. K. Janev and H. W. Drawin, eds.), Elsevier, Amsterdam (1993).Google Scholar

Copyright information

© Springer Science+Business Media New York 1995

Authors and Affiliations

  • R. K. Janev
    • 1
  1. 1.International Atomic Energy AgencyViennaAustria

Personalised recommendations