HAL : hal-00001901, version 1

arXiv : physics/0408082

Fiche détaillée

Récupérer au format BibTeX - EndNote - TEI - RefWorks -

Escape patterns due to ergodic magnetic limiters in tokamaks with reversed magnetic shear

Marisa Roberto 1, Elton C. Da Silva 2, Ibere L. Caldas 2, Ricardo L. Viana 3

(18/08/2004)

In this work we study the ergodic magnetic limiters (EML) action on field lines from the point of view of a chaotic scattering process, considering the so-called exit basins, or sets of points in the chaotic region which originate field lines hitting the wall in some specified region. We divide the tokamak wall into three areas of equal poloidal angular length, corresponding to different exits for a chaotic field line. In order to obtain the exit basins we used a fine grid chosen inside a small rectangle which comprises a representative part of the chaotic region near the wall. Thus, exit basins were obtained for a tokamak wall with reversed magnetic shear. The nontwist mapping describes the perturbed magnetic field lines with two twin chains of magnetic islands and chaotic field lines in their vicinity. For a perturbing resonant magnetic field with a fixed helicity, the observed escape pattern changes with the perturbation intensity.

1 :	Instituto Tecnológico de Aeronáutica (PHYSICS DEPARTMENT)
	Instituto Tecnológico de Aeronáutica
2 :	Universidade de S. Paulo (PHYSICS INSTITUTE)
	Universidade de S. Paulo
3 :	Universidade Federal do Paraná (PHYSICS DEPARTMENT)
	Universidade Federal do Paraná

Domaine

:

Physique/Physique/Physique des plasmas

Mots Clés : ergodic magnetic limiters exit basins reverssed magnetic shear

hal-00001901, version 1

http://hal.archives-ouvertes.fr/hal-00001901

oai:hal.archives-ouvertes.fr:hal-00001901

Contributeur : Marisa Roberto <>

Soumis le : Mercredi 18 Août 2004, 09:37:44

Dernière modification le : Mercredi 18 Août 2004, 10:12:27