Abstract Details
Abstracts
Author: Peter Manz
Requested Type: Consider for Invited
Submitted: 2026-03-08 12:58:45
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University of Greifswald
Felix-Hausdorff-Str. 6
Greifswald, 17489
Deutschland
Abstract Text:
The semi-empirical Separatrix Operational Space (SepOS) concept enables to consider power exhaust and confinement requirements together, remaining within the permitted limits of the operational space of the tokamak. The operational space of a tokamak is limited by various effects. If one looks at them individually, they scale into areas where the operational space is limited by other effects. For example, the scaling of the L-H transition power threshold delivers values for densities above the density limit, although these cannot be reached. Or the power dependence of the density limit in the L-mode provides powers above the L-H transition. In the SepOS concept [1], the disruptive density limit in L-mode, the access to high confinement (H-mode) [1,2], the maximum achievable separatrix density in H-mode and sustainment of H-mode at high density (HDL) [3] are taken into account to determine the boundaries of tokamak operation. These are drawn in a separatrix density-temperature diagram. The quantities density and temperature are not abstract and intuitively easier to understand than dimensionless parameters. The holistic perspective then unfolds fully in combination with scaling laws [4]. These allow to monitor the key parameters for power exhaust requirements (separatrix density, power width and power crossing the separatrix) at the same time. It is possible to distinguish between the ELMy regime and EDA or QCE regimes [5]. SepOS was developed for ASDEX Upgrade but is also in good agreement with Alcator C-mod [6].
References
[1] T. Eich and P. Manz Nucl. Fusion 61 086017 (2021), P. Manz, T. Eich, O. Grover Rev. Mod. Plasma Phys. 9, 5 (2025) [2] O. Grover et al Nucl. Fusion 64 056020 (2024) [3] P. Manz, T. Eich, O. Grover, Nucl. Fusion 63 076026 (2023) [4] T. Eich et al Nucl. Fusion 60 056016 (2020) [5] M. Faitsch et al Nucl. Fusion 63 076013 (2023) [6] M.A. Miller et al Nucl. Fusion 65 052002 (2025)
Characterization: 2.0
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