High-throughput full-f gyrokinetics of the tokamak boundary
Abstract
Full-f gyrokinetics of the tokamak boundary have so far been limited to individual, expert-curated cases. We report hundreds of concurrent and unsupervised simulations of the edge and scrape-off layer (SOL) in a geometry based on the Tokamak à Configuration Variable (TCV), scanning triangularity, elongation and heating power, each evolving turbulence for more than a millisecond, i.e. about two energy confinement times. Without tuned transport coefficients or experimental inputs, the ensemble reproduces the range of SOL heat-flux decay lengths measured in TCV, as well as the reduced SOL density fluctuations and the improved confinement of negative triangularity. The effect of triangularity on confinement is power dependent. At high power, negative triangularity improves the ion energy confinement by weakening the dominant microinstability rather than by a stronger sheared flow. At low power, positive triangularity flattens the ion temperature profile across the separatrix, which we attribute to a longer distance between the trapped ions and the cold recycling source. Local linear gyrokinetic calculations and the transport coefficients extracted from the turbulent fluxes consistently indicate a trapped-electron-mode regime, in which the conductive heat flux at the separatrix is carried by the electrons and the ion energy transport is convective. This article details the simulation setup, the ensemble statistics and the verification of the results, which are also summarized in a companion Letter.
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BibTeX
@misc{hoffmann2026highthroughput,
title = {{High-throughput full-f gyrokinetics of the tokamak boundary}},
author = {A. C. D. Hoffmann and M. Francisquez and T. N. Bernard and G. W. Hammett},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2605.01117},
eprint = {2605.01117},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.01117},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - High-throughput full-f gyrokinetics of the tokamak boundary
AU - A. C. D. Hoffmann
AU - M. Francisquez
AU - T. N. Bernard
AU - G. W. Hammett
PY - 2026
DA - 2026/10/10
PB - arXiv
DO - 10.48550/arxiv.2605.01117
UR - https://arxiv.org/abs/2605.01117
AB - Full-f gyrokinetics of the tokamak boundary have so far been limited to individual, expert-curated cases. We report hundreds of concurrent and unsupervised simulations of the edge and scrape-off layer (SOL) in a geometry based on the Tokamak à Configuration Variable (TCV), scanning triangularity, elongation and heating power, each evolving turbulence for more than a millisecond, i.e. about two energy confinement times. Without tuned transport coefficients or experimental inputs, the ensemble reproduces the range of SOL heat-flux decay lengths measured in TCV, as well as the reduced SOL density fluctuations and the improved confinement of negative triangularity. The effect of triangularity on confinement is power dependent. At high power, negative triangularity improves the ion energy confinement by weakening the dominant microinstability rather than by a stronger sheared flow. At low power, positive triangularity flattens the ion temperature profile across the separatrix, which we attribute to a longer distance between the trapped ions and the cold recycling source. Local linear gyrokinetic calculations and the transport coefficients extracted from the turbulent fluxes consistently indicate a trapped-electron-mode regime, in which the conductive heat flux at the separatrix is carried by the electrons and the ion energy transport is convective. This article details the simulation setup, the ensemble statistics and the verification of the results, which are also summarized in a companion Letter.
ER -