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1997

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May

  

Reviews of topical problems


Attractors and frozen-in invariants in turbulent plasma


Institute ofApplied Chemical Physics, Russian Research Centre Kurchatov Institute, pl. Kurchatova 1, Moscow, 123182, Russian Federation

Work on turbulent equipartitions in a plasma (i. e., attractors characterized by Lagrangian invariants) is reviewed. Although such attractors also exist in the convective zone of the Sun and in atmospheres, the primary emphasis is on turbulent transport in tokamaks. By extending the hydrodynamic concept of freezing-in to Vlasov’s equation, it is explained why the magnetic field topology in a collisionless plasma is conserved even though the conventional hydrodynamic description breaks down. Arguments are presented to support the conjecture that the canonical profiles of tokamak plasma are due to an attractor with a plasma frozen into the poloidal magnetic field. In fact, the exclusion from the conventional set of frozen-in integrals of the one for the toroidal magnetic field is all what is needed. The reason for the break-down of this invariant is the poloidal noninvariancy of the magnetic field, an effect to which trapped particles are particularly sensitive. The predictions of the attractor and of two attraction basin boundaries (H- mode and transport suppression by the reversed shear) are confirmed experimentally to a reasonable accuracy.

Text can be downloaded in Russian. English translation is available on IOP Science.
PACS: 52.30.−q, 52.35.Ra, 52.55.Fa (all)
DOI: 10.1070/PU1997v040n05ABEH000235
URL: https://ufn.ru/en/articles/1997/5/b/
Citation: Yan’kov V V "Attractors and frozen-in invariants in turbulent plasma" Phys. Usp. 40 477–493 (1997)
BibTexBibNote ® (generic)BibNote ® (RIS)Medline RefWorks
RT Journal
T1 Attractors and frozen-in invariants in turbulent plasma
A1 Yan’kov,V.V.
PB Physics-Uspekhi
PY 1997
FD 10 May, 1997
JF Physics-Uspekhi
JO Phys. Usp.
VO 40
IS 5
SP 477-493
DO 10.1070/PU1997v040n05ABEH000235
LK https://ufn.ru/en/articles/1997/5/b/

:    «A     » 167 499–516 (1997); DOI: 10.3367/UFNr.0167.199705b.0499

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