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Application of catastrophe theory to a point model for bumpy tori with neoclassical non-resonant electrons

Published online by Cambridge University Press:  13 March 2009

Alkesh Punjabi
Affiliation:
Department of Physics, College of William and Mary, Williamsburg, Virginia 23185
George Vahala
Affiliation:
Department of Physics, College of William and Mary, Williamsburg, Virginia 23185

Abstract

The point model of Hedrick et al. for the toroidal core plasma in the ELMO Bumpy Torus (with neoclassical non-resonant electrons) is examined in the light of catastrophe theory. Even though the point model equations do not constitute a gradient dynamic system, the equilibrium surfaces are similar to those of the canonical cusp catastrophe. The point model is then extended to incorporate ion cyclotron resonance heating. A detailed parametric study of the equilibria is presented. Further, the nonlinear time evolution of these equilibria is studied, and it is observed that the point model obeys the delay convention (and hence hysteresis) and shows catastrophes at the fold edges of the equilibrium surfaces. Although a detailed analysis of the basin boundaries for the simultaneous point attractors is not made, some simple examples are given which illustrate that the final equilibrium state can be drastically affected, not only by the control parameters (neutral density, ambipolar electrostatic potential, electron and ion cyclotron power densities) but also by the initial conditions of the state vector (plasma density, electron and ion temperatures). Tentative applications are made to experimental results.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

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References

REFERENCES

Agarwal, G. S. & Shenoy, S. R. 1981 Phys. Rev. A23, 2719.CrossRefGoogle Scholar
Dandl, R. A. et al. 1978 Oak Ridge National Laboratory Report, ORNL-TM-6457.Google Scholar
Dandl, R. A. & Guest, G. E. 1981 Fusion (ed. Teller, E. A.), part B, p. 79. Academic.CrossRefGoogle Scholar
Freeman, R. L. & Jones, E. M. 1974 Culham Laboratory Report, CLM-R127.Google Scholar
Gilmore, R. 1981 Catastrophe Theory for Scientists and Engineers. Wiley-Interscience.Google Scholar
Hedrick, C. L., Jaeger, E. F., Spong, D. A., Guest, G. E., Krall, N. A., Mcbride, J. B. & Stuart, G. W. 1977 Nucl. Fusion, 17, 1237.CrossRefGoogle Scholar
Jaeger, E. F., Hedbick, C. L. & Ard, W. B. 1979 Phys. Rev. Lett. 43, 855.CrossRefGoogle Scholar
Kaufman, A. N. 1966 Plasma Physics in Theory and Application (ed. Kunkel, W. B.). McGraw-Hill.Google Scholar
Kovrizhnykh, L. M. 1972 Soviet Phys. JETP, 35, 709.Google Scholar
Poston, T. & Stewart, I. 1978 Catastrophe Theory and Its Applications. Pitman.Google Scholar
Stewart, I. 1981 Physica, 2D, 245.Google Scholar
Thom, R. 1975 Structural Stability and Morphogenesis (trans. Fowler, D. H.). Benjamin-Addison-Wesley.Google Scholar
Uckan, T., Berry, L. A., Hills, D. L. & Richards, R. K. 1982 Oak Ridge National Laboratory Report, ORNL-TM-8117.Google Scholar
Uckan, T. et al. 1981 Oak Ridge National Laboratory Report, ORNL-TM-7897.Google Scholar
Vahala, G., Punjabi, A. & Harris, E. G. 1982 Phys. Rev. Lett. 48, 680.CrossRefGoogle Scholar
Zeeman, E. C. 1977 Catastrophe Theory: Selected Papers (1972–77). Addison-Wesley.Google Scholar