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Escape patterns due to ergodic magnetic limiters in tokamaks with reversed magnetic shear
Roberto M., Da Silva E. C., Caldas I. L., Viana R. L.
http://hal.archives-ouvertes.fr/hal-00001901
Preprint, Working Paper, Document sans référence, etc.
Physique/Physique/Physique des plasmas
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
1 :  Instituto Tecnológico de Aeronáutica (PHYSICS DEPARTMENT)
http://www.ita.br
Instituto Tecnológico de Aeronáutica
Departamento de Física ITA/CTA S. José dos Campos - SP 12228-900
Brésil
2 :  Universidade de S. Paulo (PHYSICS INSTITUTE)
http://www.usp.br
Universidade de S. Paulo
Instituto de Física Universidade de S. Paulo C.P. 66318 - S. Paulo Brazil
Brésil
3 :  Universidade Federal do Paraná (PHYSICS DEPARTMENT)
Universidade Federal do Paraná
Departamento de Física Universidade Federal do Paraná CP 19081, Curitiba - Paraná, Brazil
Brésil
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.
Anglais

ergodic magnetic limiters exit basins reverssed magnetic shear
52.55.Fa 52.55.Dy
12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)

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basins_final.ps(969.9 KB)
PDF
basins_final.pdf(524.1 KB)
TEX
basins_final.tex(16.9 KB)
fig1.eps(30.4 KB)
fig2.eps(143.8 KB)
fig3a.ps(142.2 KB)
fig3b.ps(118.2 KB)
fig4a.ps(86 KB)
fig4b.ps(241.8 KB)
fig5.ps(135.8 KB)