Skip to main content

Advertisement

SpringerLink
Log in

The Microwave-Heated Bumpy Torus: A Concept for Fusion Energy

  • Review Article
  • Published:
Journal of Fusion Energy Aims and scope Submit manuscript

Abstract

In the last 3 decades, giant steps in technology and simulations capability have been made for the benefit of all magnetic fusion concepts. This is especially true for virtually a one-of-a-kind device, a microwave-driven bumpy-torus magnetic-fusion-energy system. In the 1980s, the prototype experiment was technology limited, and it was judged based on unrealistic expectations from an incomplete understanding of the machine performance. For those experiments, the machine did not achieve the theoretical stability threshold to demonstrate good plasma confinement. This paper examines the premise that the experimental platform was underpowered, which prevented acceptance of its value for fusion. In this paper, the experimental plasma scaling data with power are reviewed. If, with the advancements of technology and simulations capability of the last 30 years, stable operation can be proven, a much improved device competitive with tokamak and stellarator performance may be possible. The advantages of this concept include steady-state operation, gentle shut down, modular construction for fabrication and maintenance, and the natural diversion of impurities.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10

Similar content being viewed by others

References

  1. M. Lubell, J.A. Clinard, J.W. Lue, J.N. Luton, T.J. McManamy, S.S. Shen, in A Review of the Structural Aspects of the Large Coil Project, ORNL report, CONF-870812-8, 9th International Conference Structural Mechanics Reactor Technology, Lausanne, Switzerland, 17–21 August 1987

  2. R.A. Dandl, H.O. Eason, A.C. England, J.C. Sprott, Nucl. Fusion 13, 693 (1973)

    Article  Google Scholar 

  3. M. Hirsch, A. Dinklage, A. Alonso, G. Fuchert, T. Klinger et al., IAEA Fusion Energy Conference, Confinement in Wendelstein 7-X Limiter Plasmas, paper EX/4-5, Kyoto, Japan, October 2016

  4. T. Klinger, C. Baylard, C.D. Beidler, J. Boscary, H.S. Bosch, A. Dinklage, D. Hartmann, P. Helander, H. Maßberg, A. Peacock, T.S. Pedersen, T. Rummel, F. Schauer, L. Wegener, R. Wolf, Fusion Eng. Des. 88, 461 (2013)

    Article  Google Scholar 

  5. In May 2011, a casual request concerning such a gyrotron source was considered by Communications and Power Industries, the same scientists under a different banner, with the estimate that it could be done for ~$2/W. Subsequently, when funding disappeared, CPI work at 170 GHz stalled, but a prototype 1-MW source has been demonstrated for short pulses and has run at ~340 kW for long pulses. Kevin Felch, private communications

  6. E.F. Jaeger, L.L. Lao, L.W. Owen, C.L. Hedrick, EBT Transport in 2-D Mirror Geometry with Finite Electron Annulus Pressure, ORNL/TM-7557, December 1980

  7. C.R. Sovinec, A.H. Glasser, T.A. Gianakon, D.C. Barnes, R.A. Nebel, S.E. Kruger, D.D. Schnack, S.J. Plimpton, A. Tarditi, M.S. Chu, J. Comput. Phys. 195, 355 (2004)

    Article  ADS  Google Scholar 

  8. S. Ku, C.S. Chang, P.H. Diamond, Nucl. Fusion 49, 115021 (2009)

    Article  ADS  Google Scholar 

  9. R. Hager, E.S. Yoon, S. Ku, E.F. Azevedo, P.H. Worley, C.S. Chang, J. Comput. Phys. 315, 644 (2016)

    Article  ADS  MathSciNet  Google Scholar 

  10. R.A. Dandl, G.E. Guest, Fusion, in Magnetic Confinement Part B, Chapter 11, vol. 1, ed. by E. Teller (The Elmo Bumy Torus, Elsevier Science, Amsterdam, 1981), pp. 79–101

    Google Scholar 

  11. S. Hiroe, R.J. Colchin, G.R. Haste, F.W. Baity, D.D. Bates, L.A. Berry, T.S. Bigelow, R.D. Burris, J.A. Cobble, W.A. Davis, R.D. Donaldson, J.C. Glowienka, D.L. Hillis, H.D. Kimrey, R.L. Livesey, J.B. Mankin, M.W. McGuffin, D.R. Overby, B.G. Peterson, D.A. Rasmussen, R.K. Richards, C.R. Shaich, G.R. Sullivan, D.W. Swain, T. Uckan, T.L. White, J.B. Wilgen, R.E. Winterberg, K.G. Young, K.A. Conner, J.R. Goyer, R.L. Hickok, L. Solenstein, F.M. Beiniosek, R.E. Juhala, T.L. Owens, D.A. Boyd, R. Mahon, V.E. Yun, B.H. Quon, O.E. Hankins, W.H. Casson, K.H. Carpenter, Nucl Fusion 28, 2249 (1988)

    Article  Google Scholar 

  12. M. Freeman, The True History of the U.S. Fusion Program—And Who Tried to Kill It, 21st Century Science and Technology Winter 2009/2010, p. 15

  13. EBT-P project status report, ORNL/Sub-81-21099/2, publisher, McDonnell Douglas, SciTech Connect (U.S. Dept. of Energy, Office of Scientific and Technical Information)

  14. M. Peng, Private communication

  15. R.A. Dory, N.A. Uckan, Q.B. Ard, D.B. Bachelor, L.A. Berry, W.E. Bryan, R.A. Dandl, G.E. Guest, G.R. Haste, D.E. Hastings, C.L. Hedrick, D.K. Lee, T.J. McManamy, R.L. Miller, L.W. Owen, J.F. Pipkins, R.J. Schmidt, J. Sheffield, D.A. Spong, P.B. Thompson, J.S. Tolliver, T. Uckan, W.L. Wright, ELMO Bumpy Square Proposal, ORNL/TM-9994, 1986

  16. G. Guest, Electron Cyclotron Heating of Plasmas, Chapter 8 (Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2009)

    Book  Google Scholar 

  17. E.F. Jaeger, L.A. Berry, C.L. Hedrick, R.K. Richards, Nucl. Fusion 25, 71 (1985)

    Article  Google Scholar 

  18. R.A. Dandl, R.A. Dory, H.O Eason, G.E. Guest, G.R. Haste, C.L. Hedrick, H. Ikegami, E.F. Jaeger, N.H. Lazar, J.N. Luton, D. G. McAlees, D.H. McNeill, D.B. Nelson, in Research Program for Plasma Confinement and Heating in Elmo Bumpy Torus Devices, ORNL-TM-4941, June 1975

  19. K.H. Carpenter, R.A. Dandl, M.W. McGuffin, in Calibration of a Diamagnetic Diagnostic for Stored Energy of High Temperature Electron Annuli in Elmo Bumpy Torus (EBT), ORNL/TM-7076, 1982

  20. Electron stopping power may be calculated from http://physics.nist.gov/PhysRefData/Star/Text/ESTAR.html

  21. A.M. El Nadi, J.C. Whitson, Phys. Fluids 26, 1327 (1983)

    Article  ADS  Google Scholar 

  22. D.H. McNeill, in Thomson Scattering Determination of Electron Temperature in ELMO Bumy Torus (EBT), Topical Conference on Diagnostics of High Temperature Plasmas, American Physical Society, Knoxville, TN, January 7–9, 1976

  23. D.L. Hillis, G.R. Haste, L.A. Berry, Phys. Fluids 26, 820 (1983)

    Article  ADS  Google Scholar 

  24. J.A. Cobble, Rev. Sci. Instrum. 56, 1018 (1985)

    Article  ADS  Google Scholar 

  25. D.W. Swain, J.A. Cobble, D.L. Hillis, R.K. Richards, T. Uckan, Phys. Fluids 26, 1922 (1985)

    Article  ADS  Google Scholar 

  26. J.A. Cobble, Thomson Scattering on ELMO Bumpy Torus, ORNL-TM-9471, April 1985

  27. P.L. Colestock, K.A. Conner, R.L. Hickok, Phys. Rev. Lett. 40, 1717 (1978)

    Article  ADS  Google Scholar 

  28. F.M. Bieniosek, K.A. Conner, Phys. Fluids 26, 2256 (1983)

    Article  ADS  Google Scholar 

  29. D.L. Hillis, J.B. Wilgen, T.S. Bigelow, E.F. Jaeger, D.W. Swain, O.E. Hankins, R.E. Juhala, Phys. Fluids 29, 3796 (1986)

    Article  ADS  Google Scholar 

  30. Design Features of the ELMO Bumpy Square, Oak Ridge National Laboratory, CONF-851102-39; TI86003811

  31. H.P. Furth, T.K. Fowler, H. Dreicer, J. Fusion Energ. 4, Nos. 2/3, 101 (1985)

  32. C. Watts, V. Udintsev, P. Andrew, G. Vayakis, M. Van Zeeland, D. Brower, R. Feder, E. Mukhin, S. Tolstyakov, Nucl. Instrum. Methods Phys. Res. A 720, 7 (2013)

    Article  ADS  Google Scholar 

  33. S.K. Borowski, N.A. Uckan, E.F. Jaeger, T. Kammash, Nucl. Fusion 20, 177 (1980)

    Article  ADS  Google Scholar 

  34. T.L. White, H.D. Kimrey, T.S. Bigelow, T.S. Bates, H.O. Eason, Int. J. Infrared Millim. Waves 5, 1129 (1984)

    Article  ADS  Google Scholar 

  35. N.A. Uckan, E.F. Jaeger, RT. Santoro, D.A. Spong, T. Uckan, L.W. Owen, J.M. Barnes, J.B. McBride, EBT Reactor Analysis, ORNL/TM-8712, August 1983

  36. L.W. Owen, N.A. Uckan, J. Fusion Energ. 1, 341 (1981)

    Article  ADS  Google Scholar 

  37. E.M. Hollmann, P.B. Aleynikov, T. Fülop, D.A. Humphreys, V.A. Izzo, M. Lehnen, V.E. Lukash, G. Papp, G. Pautasso, F. Saint-Laurent, J.A. Snipes, Phys. Plasmas 22, 021802 (2015). This paper describes the challenge of mitigating tokamak disruptions with 350 MJ of stored energy. Converting this energy to tons of high explosives, the result is ~ 170 lb

Download references

Acknowledgements

The author acknowledges the scientists with whom he worked at ORNL over 30 years ago, particularly, colleagues Don Hillis, David Rasmussen, Larry Owen, Don Spong, and others who helped reach the conclusions of this paper. Gareth Guest offered a voice of encouragement. This manuscript is dedicated to Ray Dandl, who admitted me into his group as a student to work on the ELMO mirror machine in 1972. His confinement concept had an appeal to me for its simplicity, and perhaps almost 45 years later, I understand it better. I close with an anecdote from the EBT control room that occurred in the 1970s. We still lived then under the illusion that one could make non-perturbing Langmuir probe measurements in a hot plasma. We had started up the microwave drive on this occasion and lowered the gas pressure to enter the T mode. From the previous day’s operations, a technician had disconnected a Langmuir probe cable but had forgotten to withdraw the probe from the plasma volume. When the plasma space potential exceeded the Paschen threshold, the disconnected BNC cable on the floor began arcing—several hundred volts. The space potential and the associated E × B drifts are critical for stability, and Hiroe covers this topic well in Ref. [11]. If the thesis of this paper is correct, the space-potential profile in a new, improved device could be radically different from Ref. [11] and much more favorable. We should find out. This work has been performed under the auspices of the United States Department of Energy, Contract No. DE-AC52-06NA25396.

Author information

Authors and Affiliations

  1. Los Alamos National Laboratory, Los Alamos, NM, 87545, USA

    J. A. Cobble

Authors
  1. J. A. Cobble
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to J. A. Cobble.

Additional information

J. A. Cobble—Retired from Los Alamos National Laboratory, Los Alamos.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Cobble, J.A. The Microwave-Heated Bumpy Torus: A Concept for Fusion Energy. J Fusion Energ 36, 187–196 (2017). https://doi.org/10.1007/s10894-017-0139-9

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10894-017-0139-9

Keywords

Search

Navigation