Abstract Details
Abstracts
Author: Antoine C.D. Hoffmann
Requested Type: Poster
Submitted: 2025-03-14 09:12:36
Co-authors: T.N.Bernard, M.Francisquez, A.Hakim, G.W.Hammett
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator road
Princeton, New Jersey 08543
Mercer
Abstract Text:
This work presents the first flux-driven GK turbulence simulations with the Gkeyll code
[1-4] that successfully reproduce key experimental results in NT plasmas in the edge
and scrape-off layer (SOL) of TCV. Unlike previous studies, our simulations self-consistently
evolve plasma turbulence by solving the long-wavelength full-f GK equations in a global
geometry that includes both closed and open field lines. Leveraging its energy-preserving
discontinuous Galerkin scheme and field-aligned coordinates, Gkeyll can evolve milliseconds
of plasma turbulence using a GK model with kinetic electrons and ions in only a few dozens
GPU hours.
In our simulation setup, energy flows from a source located in the closed field line region
– adjusted to match the experimental input power – to the SOL, where conducting sheath
boundary conditions are applied at the limiter position. The Gkeyll predictions closely match
experimental data near the LCFS and within the SOL, demonstrating the code’s capability
to capture edge physics accurately. Experimentally, NT yields a ∼ 15% increase in electron
temperature and density profiles compared to a similar TCV discharge with positive triangularity
(PT). We report that this improvement is accurately reproduced by Gkeyll simulations. Finally,
Gkeyll results suggest that the confinement improvement observed in NT is related to the
formation of an internal transport barrier (ITB) near q = 2. These results demonstrate the
potential of using numerical tools like Gkeyll to complement experimental studies and guide
future efforts to optimize plasma performance in fusion devices.
[1] J. Juno et al., J. Comput. Phys. 353, 110-147 (2018).
[2] A. Hakim, ”The Gkeyll code: Documentation Home (2022),” https://gkeyll.readthedocs.io/.
[3] M. Francisquez et al., Comput. Phys. Commun. 298, 109109 (2024).
[4] T. N. Bernard et al., Plasma Phys. Control. Fusion 66, 115017 (2024).
Characterization: 2.0
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