THE NON-AXISYMMETRIC MAGNETIC SEPARATRIX IN FUSION PLASMAS
David Ciro1; Iberê Caldas1
1 University of Sao Paulo
Resumo
The magneto-hydrodynamic (MHD) equilibrium of fusion plasmas is nominally axisymmetric, presenting nested toroidal magnetic surfaces enclosed by a homoclinic separatrix. In more general situations the axial symmetry is broken by internal MHD instabilities or by the external application of 3D fields used to mitigate instabilities. In such cases, the magnetic separatrix can be redefined in terms of the perturbed magnetic saddle, leading to homoclinic lobes. In this work we present a numerical method to calculate high resolution invariant manifolds in the Poincaré section, leading to the magnetic surface delimiting the confined fieldlines for realistic tokamak discharges.
Palavras-chave: Fluidodynamics; Plasma and Turbulence; Modeling, Numerical Simulation and Optimization; Nonlinear Dynamics in Thermal and Fluid Sciences; Analysis and Control of Nonlinear Dynamical Systems with Practical Applications