Onset of internal transport barriers in tokamaks

Autor(es)

Osorio, L. A. ^[1] ; Roberto, M. ^[2] ; Caldas, I. L. ^[1] ; Viana, R. L. ^[3] ; Elskens, Y. ^[4]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: Physics of Plasmas; v. 28, n. 8 AUG 2021.
• Citações Web of Science: 0

Resumo

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)

• Processo FAPESP: 18/14435-2 - Transporte e turbulência em plasmas
• Beneficiário: Marisa Roberto
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/03211-6 - Dinâmica não linear
• Beneficiário: Iberê Luiz Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 20/01399-8 - Mapas simpléticos em um plasma confinado magneticamente
• Beneficiário: Leonardo Antonio Osorio Quiroga
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto