Nontwist field line mapping in a tokamak with ergodic magnetic limiter

Autor(es)

Mugnaine, Michele ; Caldas, Ibere L. ; Szezech Jr, Jose D. ; Viana, Ricardo L.

• Tipo de documento: Artigo Científico
• Fonte: PHYSICAL REVIEW E; v. 108, n. 5, p. 12-pg., 2023-11-13.

Resumo

For tokamaks with uniform magnetic shear, Martin and Taylor have proposed a symplectic map which has been used to describe the magnetic field lines at the plasma edge perturbed by an ergodic magnetic limiter. We propose an analytical magnetic field line map, based on the Martin-Taylor map, for a tokamak with arbitrary safety factor profile. With the inclusion of a nonmonotonic profile, we obtain a nontwist map which presents the characteristic properties of degenerate systems, such as the twin islands scenario, shearless curve, and separatrix reconnection. We estimate the width of the islands and describe their changes of shape for large values of the limiter current. From our numerical simulations about the shearless curve, we show that its position and aspect depend on the control parameters. (AU)

• Processo FAPESP: 18/03211-6 - Dinâmica não linear
• Beneficiário: Iberê Luiz Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 22/12736-0 - Oscilações em plasmas confinados magnéticamente
• Beneficiário: Michele Mugnaine
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado