Nonlinear dynamics of feedback modulated magnetic islands in toroidal plasmas
Phys. Plasmas 7, 4983 (2000); doi:10.1063/1.1318360
Issue Date: December 2000
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An analysis is presented of the dynamics of a helical magnetic island chain embedded in a toroidal plasma, in the presence of an externally imposed, rotating, magnetic perturbation of the same helicity. Calculations are carried out in the large aspect-ratio, zero-
, resistive magnetohydrodynamical limit, and incorporate a realistic treatment of plasma viscosity. There are three regimes of operation, depending on the modulation frequency (i.e., the difference in rotation frequency between the island chain and the external perturbation). For slowly modulated islands, the perturbed velocity profile extends across the whole plasma. For strongly modulated islands, the perturbed velocity profile is localized around the island chain, but remains much wider than the chain. Finally, for very strongly modulated islands, the perturbed velocity profile collapses to a boundary layer on the island separatrix, plus a residual profile which extends a few island widths beyond the separatrix. Analytic expressions are obtained for the perturbed velocity profile, the island equation of motion, and the island width evolution equation in each of these three regimes. The ion polarization correction to the island width evolution equation, which has previously been reported to be stabilizing, is found to be destabilizing in all three regimes. ©2000 American Institute of Physics.
, resistive magnetohydrodynamical limit, and incorporate a realistic treatment of plasma viscosity. There are three regimes of operation, depending on the modulation frequency (i.e., the difference in rotation frequency between the island chain and the external perturbation). For slowly modulated islands, the perturbed velocity profile extends across the whole plasma. For strongly modulated islands, the perturbed velocity profile is localized around the island chain, but remains much wider than the chain. Finally, for very strongly modulated islands, the perturbed velocity profile collapses to a boundary layer on the island separatrix, plus a residual profile which extends a few island widths beyond the separatrix. Analytic expressions are obtained for the perturbed velocity profile, the island equation of motion, and the island width evolution equation in each of these three regimes. The ion polarization correction to the island width evolution equation, which has previously been reported to be stabilizing, is found to be destabilizing in all three regimes. ©2000 American Institute of Physics.
| History: | Received 9 May 2000; accepted 23 August 2000 |
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KEYWORDS and PACS
- 52.30.-q
Physics of plasmas and electric discharges Plasma flow; magnetohydrodynamics - 52.35.Py
Physics of plasmas and electric discharges Waves, oscillations, and instabilities in plasma Plasma macroinstabilities (hydromagnetic, e.g., kink, fire-hose, mirror, ballooning, tearing, trapped-particle, flute, RayleighTaylor, etc.) - 52.55.Hc
Physics of plasmas and electric discharges Magnetic confinement and equilibrium Stellarators, spheromaks, compact tori, bumpy tori, and other toroidal confinement devices - YEAR: 2000
RELATED DATABASES
PUBLICATION DATA
1070-664X (print)
1089-7674 (online)
REFERENCES (39)
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- T. Taylor, E. J. Strait, L. L. Lao et al., Phys. Plasmas 2, 2390 (1995).
- T. Ivers, E. Eisner, A. Garafalo et al., Phys. Plasmas 3, 1926 (1996).
- O. Sauter, R. J. La Haye, Z. Chang et al., Phys. Plasmas 4, 1654 (1997).
- J. S. Sarff, N. E. Lanier, S. C. Prager, and M. R. Stoneking, Phys. Rev. Lett. 78, 62 (1997).
- M. N. Rosenbluth,
Plasma Phys. Controlled Fusion 41, A99 (1999) . - H. P. Furth, J. Killeen, and M. N. Rosenbluth, Phys. Fluids 6, 459 (1963).
- J. A. Wesson,
Nucl. Fusion 18, 87 (1978) . - R. Carrera, R. D. Hazeltine, and M. Kotschenreuther, Phys. Fluids 29, 899 (1986).
- P. H. Rutherford, Phys. Fluids 16, 1903 (1973).
- R. B. White, D. A. Monticello, M. N. Rosenbluth, and B. V. Waddell, Phys. Fluids 20, 800 (1977).
- A. Thyagaraja, Phys. Fluids 24, 1716 (1981).
- Z. Chang and J. D. Callen,
Nucl. Fusion 30, 219 (1990) . - B. V. Chirikov,
J. Nucl. Energy, Part C 1, 253 (1960) . - M. N. Rosenbluth, R. Z. Sagdeev, J. B. Taylor, and G. M. Zaslavski,
Nucl. Fusion 6, 297 (1966) . - A. B. Rechester and M. N. Rosenbluth, Phys. Rev. Lett. 40, 38 (1978).
- V. V. Arsenin, L. I. Artemenkov, N. V. Ivanov et al., in Proceedings of the 16th International Conference Innsbruck (IAEA, Vienna, 1979), Vol. I, p. 233.
- A. W. Morris, T. C. Hender, J. Hugill et al., Phys. Rev. Lett. 64, 1254 (1990).
- G. A. Navratil, C. Cates, M. E. Mauel et al., Phys. Plasmas 5, 1855 (1998).
- P. H. Rutherford, Proceedings of Course and Workshop on Basic Physical Processes of Toroidal Fusion Plasmas (Commission of the European Communities, Brussels, 1985), Vol. 2, p. 531.
- A. H. Glasser, J. M. Greene, and J. L. Johnson, Phys. Fluids 18, 875 (1975).
- M. Kotschenreuther, R. D. Hazeltine, and P. J. Morrison, Phys. Fluids 28, 294 (1985).
- G. Ara, B. Basu, B. Coppi, G. Laval, M. N. Rosenbluth, and B. V. Waddell,
Ann. Phys. (N.Y.) 122, 443 (1978) . - A. I. Smolyakov,
Plasma Phys. Controlled Fusion 35, 657 (1993) . - M. Zabiego and X. Garbet, Phys. Plasmas 1, 1890 (1994).
- R. Fitzpatrick and T. C. Hender, Phys. Fluids B 3, 644 (1991).
- A. I. Smolyakov, A. Hirose, E. Lazzaro, G. B. Re, and J. D. Callen, Phys. Plasmas 2, 1581 (1995).
- H. R. Wilson, J. W. Connor, R. J. Hastie, and C. C. Hegna, Phys. Plasmas 3, 248 (1996).
- F. L. Waelbroeck and R. Fitzpatrick, Phys. Rev. Lett. 78, 1703 (1997).
- A. H. Boozer, Phys. Plasmas 3, 4620 (1996).
- E. Lazzaro and M. F. F. Nave, Phys. Fluids 31, 1623 (1988).
- G. Bosia and E. Lazzaro,
Nucl. Fusion 31, 1003 (1991) . - The standard large aspect-ratio ordering is R0/a
1, where R0 and a are the major and minor radii of the plasma, respectively. - The conventional definition of this parameter is
= 2µ0
p
/
B2
, where 
![[centered ellipsis]](http://scitation.aip.org/stockgif2/cellip.gif)
denotes a volume average, p is the plasma pressure, and B is the magnetic field-strength. - W. A. Newcomb,
Ann. Phys. (N.Y.) 10, 232 (1960) . - R. Fitzpatrick, Phys. Plasmas 6, 1168 (1999).
- R. Fitzpatrick,
Nucl. Fusion 33, 1049 (1993) . - R. Fitzpatrick, S. C. Guo, D. J. Den Hartog, and C. C. Hegna, Phys. Plasmas 6, 3878 (1999).
- R. Fitzpatrick, Phys. Plasmas 5, 3325 (1998).
- T. H. Stix, Phys. Fluids 16, 1260 (1973).







