Stochastic properties of the magnetic field lines in the presence of current sheets

S. Bulanov, D. Farina

Research output: Contribution to journalArticle

Abstract

The process of separatrix broadening under the action of periodic perturbations is investigated in the case when the equilibrium magnetic configuration contains current sheets. The change of the magnetic field topology due to the presence of current sheets is discussed, and compared to the case of the standard figure-eight separatrix. In this case, the Hamiltonian structure of the magnetic field separatrix modifies due to the presence of Y-points instead of X-points. Contrary to the case of X-points, the period of the motion is always finite, and experiences a finite jump when the trajectory in the phase plane crosses the separatrix. This fact leads to the appearance of a stochastic layer. This phenomenon is of relevance in the analysis of the processes arising in the nonlinear stage of the m=1 mode instability in a tokamak magnetic field.
Original languageEnglish
Pages (from-to)284 - 287
Number of pages4
JournalPhysica Scripta
Volume63
Publication statusPublished - 1996
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • Mathematical Physics
  • Condensed Matter Physics
  • Physics and Astronomy(all)

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