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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Onset of internal transport barriers in tokamaks

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Author(s):
Osorio, L. A. [1] ; Roberto, M. [2] ; Caldas, I. L. [1] ; Viana, R. L. [3] ; Elskens, Y. [4]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo, SP - Brazil
[2] Inst Tecnol Aeronaut, Dept Fis, BR-1228900 Sao Jose Dos Campos, SP - Brazil
[3] Univ Fed Parana, Dept Fis, BR-81531990 Curitiba, PR - Brazil
[4] Aix Marseille Univ, UMR 7345 CNRS, PIIM, Campus St Jerome, Case 322, FR-13397 Marseille 13 - France
Total Affiliations: 4
Document type: Journal article
Source: Physics of Plasmas; v. 28, n. 8 AUG 2021.
Web of Science Citations: 0
Abstract

Barriers have been identified in magnetically confined plasmas by reducing the particle transport and improving the confinement. One of them, the primary shearless barriers, is associated with extrema of non-monotonic plasma profiles. Previously, we identified these barriers in a model described by a map that allows the integration of charged particles motion in drift waves for a long timescale. In this work, we show how the existence of these robust barriers depends on the fluctuation amplitude and on the electric shear. Moreover, we also find control parameter intervals for which these primary barriers onset and breakup are recurrent. Another noticeable feature, in these transitions, is the appearance of a layer of particle trajectory stickiness after the shearless barrier breakup or before its onset. In addition to the mentioned primary barriers, we also observe sequences of secondary shearless barriers, not reported before, created and destroyed by a sequence of bifurcations as the main control parameters, the fluctuation amplitude and electric shear, are varied. Furthermore, in these bifurcations, we also find hitherto unknown double and triple secondary shearless barriers that constitute a noticeable obstacle to the chaotic transport. (AU)

FAPESP's process: 18/14435-2 - Transport and Turbulence in Plasmas
Grantee:Marisa Roberto
Support Opportunities: Regular Research Grants
FAPESP's process: 18/03211-6 - Non linear dynamics
Grantee:Iberê Luiz Caldas
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 20/01399-8 - Symplectic maps for magnetically confined plasmas
Grantee:Leonardo Antonio Osorio Quiroga
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)