2013/08/22 by P. Rodrigues, Paulo Rodrigues, Nuno Loureiro +4 · 1 citation
Physics and Astronomy · #Asymmetry #Atomic physics #Bootstrap current #Computational physics #Core (optical fiber) #Ionosphere and magnetosphere dynamics #Magnetic confinement fusion research #Magnetic field #Materials science #Mechanics #Nuclear physics #Optics #Perturbation (astronomy) #Physics #Plasma #Shear (geology) #Solar and Space Plasma Dynamics #Tokamak #Toroid #physics.plasm-ph
paper · pdf · doi:10.1088/0029-5515/54/9/093003
published as Nucl. Fusion 54, 093003 (2014) · 6 pages, 2 figures, submitted for publication
arxiv created 2013/08/22 · openalex publication_date 2014/07/30 · arxiv updated 2014/10/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A local magnetic equilibrium solution is sought around the magnetic axis in order to identify the key parameters defining the magnetic-surface's up-down asymmetry in the core of tokamak plasmas. The asymmetry is found to be determined essentially by the ratio of the toroidal current density flowing on axis to the fraction of the external field's odd perturbation that manages to propagate from the plasma boundary into the core. The predictions are tested and illustrated first with an analytical Solovev equilibrium and then using experimentally relevant numerical equilibria. Hollow current-density distributions, and hence reverse magnetic shear, are seen to be crucial to bring into the core asymmetry values that are usually found only near the plasma edge.