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Title: Variational approach for static mirror structures

Anisotropic static plasma equilibria where the parallel and perpendicular pressures are only functions of the amplitude of the local magnetic field are shown to be amenable to a variational principle with a free energy density given by the parallel tension. This approach is used to demonstrate that two-dimensional small-amplitude static magnetic holes constructed from a Grad-Shafranov type equation slightly below the (subcritical) mirror instability threshold identify with lump solitons of KPII equation, but turn out to be unstable. Differently, large-amplitude magnetic structures, which are stable as they realize a minimum of the free energy, are computed using a gradient method within two-dimensional numerical simulations where the regularizing effect of finite Larmor radius corrections is retained. Interestingly, these structures transform from stripes to bubbles when the angle of the magnetic field with the coordinate plane is increased.
Authors:
 [1] ;  [2] ;  [2] ; ;  [3] ;  [4]
  1. P.N. Lebedev Physical Institute RAS, 53 Leninsky Ave., 119991 Moscow (Russian Federation)
  2. (Russian Federation)
  3. UNS, CNRS, Observatoire de la Côte d'Azur, CS 34229, 06304 Nice Cedex 4 (France)
  4. L.D. Landau Institute for Theoretical Physics RAS, 2 Kosygin str., 119334 Moscow (Russian Federation)
Publication Date:
OSTI Identifier:
22408298
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 22; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AMPLITUDES; ANISOTROPY; BUBBLES; COMPUTERIZED SIMULATION; CORRECTIONS; ENERGY DENSITY; EQUATIONS; FREE ENERGY; LARMOR RADIUS; MAGNETIC FIELDS; MIRRORS; PLASMA; PLASMA PRESSURE; SOLITONS; TWO-DIMENSIONAL CALCULATIONS; TWO-DIMENSIONAL SYSTEMS; VARIATIONAL METHODS