Speaker
Description
Symmetry‑breaking perturbations in fusion plasmas—whether produced by intrinsically excited magnetohydrodynamic modes such as Alfvénic Eigenmodes and Geodesic Acoustic Modes, or by externally applied fields such as Resonant Magnetic Perturbations and Toroidal‑Field ripples—interact with charged particles through resonances that govern the transport of particles, energy, and momentum. Building on our earlier analysis for large‑aspect‑ratio equilibria [1–5], we generalize Orbital Spectrum Analysis (OSA) to numerically reconstructed, realistic tokamak equilibria. A computationally efficient semi-analytical geometrical method yields Guiding Center orbital frequencies and the kinetic safety factor for any given unperturbed axisymmetric equilibrium. The resulting resonance diagrams pinpoint all mode-particle resonances and locate transport barriers at the extrema of the kinetic safety factor. Systematic comparisons with numerical particle tracing validate the predicted resonance and transport barrier positions with excellent agreement for thermal and energetic particles alike. The methodology therefore furnishes a computationally efficient tool for assessing the response of all particle species to multi‑scale symmetry‑breaking perturbations in realistic equilibria.
References
[1] P.A. Zestanakis, Y. Kominis, G. Anastassiou and K. Hizanidis, Phys. Plasmas 23, 032507 (2016)
[2] Y. Antonenas, G. Anastassiou and Y. Kominis, J. Plasma Phys. 87, 855870101 (2021)
[3] H.T. Moges, Y. Antonenas, G. Anastassiou, Ch. Skokos and Y. Kominis, Phys. Plasmas 31, 012302 (2024)
[4] G. Anastassiou, P. Zestanakis, Y. Antonenas, E. Viezzer and Y. Kominis, J. Plasma Phys. 90, 905900110 (2024)
[5] Y. Antonenas, G. Anastassiou and Y. Kominis, Phys. Plasmas 31, 102302 (2024)
