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1997

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Reviews of topical problems


Attractors and frozen-in invariants in turbulent plasma


Institute of Applied 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.

Fulltext pdf (303 KB)
Fulltext is also available at DOI: 10.1070/PU1997v040n05ABEH000235
PACS: 52.30.−q, 52.35.Ra, 52.55.Fa (all)
DOI: 10.1070/PU1997v040n05ABEH000235
URL: https://ufn.ru/en/articles/1997/5/b/
A1997XJ11200002
Citation: Yan’kov V V "Attractors and frozen-in invariants in turbulent plasma" Phys. Usp. 40 477–493 (1997)
BibTexBibNote ® (generic)BibNote ® (RIS) MedlineRefWorks
PT Journal Article
TI Attractors and frozen-in invariants in turbulent plasma
AU Yan’kov V V
FAU Yan’kov VV
DP 10 May, 1997
TA Phys. Usp.
VI 40
IP 5
PG 477-493
RX 10.1070/PU1997v040n05ABEH000235
URL https://ufn.ru/en/articles/1997/5/b/
SO Phys. Usp. 1997 May 10;40(5):477-493

Îðèãèíàë: ßíüêîâ Â Â «Aòòðàêòîðû è èíâàðèàíòû âìîðîæåííîñòè â òóðáóëåíòíîé ïëàçìå» ÓÔÍ 167 499–516 (1997); DOI: 10.3367/UFNr.0167.199705b.0499

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