REVIEW 2 major objections 5 minor 51 references
Towards joint optimization of stellarator coils and support structures
T0 review · 2 major / 5 minor · reviewed 2026-07-11 · grok-4.5
Pith's one-line read Jointly optimizing stellarator coil shapes and clamp locations with differentiable FEA cuts RMS von Mises stress by 2.4× at similar field error.
desk verdict Solid methods paper: first AD joint coil–clamp optimization with clean controls and open code; the 2.4× stress drop is real inside a simplified spring-clamp model, not a reactor prediction. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
coil-fem: a fully differentiable finite-element pipeline that builds a finite-build coil mesh from a centerline, applies a spring-foundation boundary condition whose support patches move with optimizable clamp angles, solves linear elasticity, and returns gradients of stress and displacement with respect to both geometry and clamp locations.
What would settle it
Rebuild the optimized coil-and-clamp geometry in a conventional FEA code that includes a realistic cage or shell model; if the reported 2.4 imes RMS stress reduction disappears or the optimal clamp locations move substantially, the claim does not transfer.
Extended reading notes
Core claim
When coil Fourier coefficients and the parametric locations of support clamps are optimized together under a differentiable FEA load penalty, the resulting coil set achieves roughly 2.4 times lower RMS von Mises stress than an unoptimized baseline that uses fixed top-and-bottom clamps, while magnetic field error remains comparable.
Load-bearing premise
The supports are only soft spring patches glued to the coil surface with a large fixed stiffness, not a real deformable cage or shell whose flexing and load paths could change where stress actually peaks.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper introduces coil-fem, an open-source JAX-FEM-based tool that embeds differentiable linear-elasticity FEA (with spring-foundation support BCs) into stellarator coil optimization. From filamentary coils it builds finite-build rectangular meshes, applies Lorentz (Landreman–Hurwitz self-force plus mutual), gravity and uniform thermal contraction, and differentiates von Mises stress and displacement with respect to both coil Fourier coefficients and clamp parametric locations. On a simplified W7-X-like set with two clamps per coil, four controlled optimizations (clamp-only, coil-only, joint, and Lorentz-force proxy) show that joint optimization (case C) yields ~2.4 imes lower RMS von Mises stress and comparable field error relative to a fixed top/bottom-clamp baseline, while force-proxy optimization alone does not reduce stress.
Significance. If the result holds under the stated model, this is the first gradient-driven joint coil–support optimization in the stellarator literature and supplies a concrete, reproducible demonstration that clamp placement is a first-order lever on coil stress—something analytic force/torque proxies cannot capture. The open-source AD pipeline, DOLFINx cross-checks (pointwise agreement ~1e-8 when Bself is identical; RMS metrics within ~2%), and the A–D ablation suite are genuine strengths that lower the barrier to including structural FEA inside coil design loops. The work is therefore a useful proof-of-concept even though the support model is deliberately simplified.
major comments (2)
- §2.3, Eqs. (2) and (10): the central quantitative claim (2.4× RMS stress reduction) is obtained under isotropic spring-foundation patches with a single large fixed k0. The paper itself states that this BC “cannot accurately predict flexing in the support cage.” Because real cage compliance would redistribute loads and could move the optimal clamp locations, the reported factor should be presented strictly as a result inside the two-clamp homogeneous-coil model, and a short sensitivity study (or explicit caveat in the abstract/conclusions) is needed before the number is treated as transferable.
- §3.2, Eq. (11) and Table 3: the multi-objective weights, k0 = 10^10 N m^{-3}, Ncl = 2 and n = 80 are free hyperparameters. While the A–D suite cleanly isolates the effect of optimizable clamps, the manuscript does not show that the 2.4× reduction is robust to modest changes in these choices. A brief robustness check (or an explicit statement that the factor is weight- and k0-dependent) would strengthen the load-bearing claim.
minor comments (5)
- Abstract and §3.2: “unoptimized baseline” is slightly ambiguous; clarify that the baseline uses the original W7-X centerlines with fixed top/bottom clamps (distinct from the real W7-X support inventory).
- Fig. 1 caption and §3.1: the n = 275 data point is referenced but the main optimization uses n = 80; a short note on why the lower resolution is adequate for gradients would help.
- Table 1 and §2.1: the fixed-mesh-topology assumption is listed; a sentence on how large geometry changes are prevented (or remeshed) during multi-grid Fourier optimization would improve reproducibility.
- Eq. (10): the logistic sigmoid transition width ϵ_cl is never given a numerical value; please state the value used.
- References: Kaptanoglu 2026 and related arXiv preprints are cited; ensure final DOIs/versions are updated if available at publication.
Circularity Check
No circularity: joint coil-support optimization reports an empirical multi-objective result, not a quantity forced by definition or self-citation.
full rationale
The paper's central claim (case C: joint optimization of coil Fourier coefficients and clamp locations yields ~2.4× lower RMS von Mises stress at comparable field error versus a fixed top/bottom-clamp W7-X-like baseline) is an empirical outcome of a controlled A–D optimization suite, not a tautology. Field error JB (normalized squared flux on the plasma boundary) and Jload (volume integral of σv² from linear-elastic FEA) are independent external objectives; the composite penalty (Eq. 11) does not force one from the other by construction. Clamp locations enter only through the spring-foundation BC (Eqs. 2, 10), which is a modeling choice, not a fit recycled as a prediction. Related coauthor work (Kaptanoglu 2026) is cited and explicitly distinguished (fixed supports vs optimizable clamps). DOLFINx benchmarks and open code further make the FEA self-contained. No equation reduces the reported stress reduction to a normalization identity, fitted parameter, or self-citation chain. Score 0 is therefore appropriate.
Assumptions & free parameters
free parameters (5)
- spring coefficient k0
- clamp half-width rcl and transition width epsilon_cl
- multi-objective penalty weights in J (Eq. 11)
- number of clamps Ncl=2 per coil
- optimization mesh resolution n=80
assumptions (6)
- domain assumption Linear isotropic elasticity with small-strain additive thermal decomposition (Eqs. 1, 7–8)
- ad hoc to paper Spring-foundation BC is an adequate AD-compatible surrogate for cage clamps (Eqs. 2, 10)
- domain assumption Body force uses Landreman–Hurwitz self-force and filament mutual field; Fbody independent of displacement
- domain assumption Homogeneous isotropic 316LN properties and uniform current density for the entire coil body
- ad hoc to paper Fixed mesh topology during optimization; rotation-minimizing rectangular sweep for finite-build coils
- standard math Standard stellarator filament penalties (JB, length, spacing, linking, curvature) as in prior coil optimization literature
invented entities (2)
-
coil-fem differentiable FEA pipeline
independent evidence
-
Sigmoid-sum spring field k(x,{phi_i}) for movable clamps
Cite this review
Pith. "Pith review of Towards joint optimization of stellarator coils and support structures." pith.science (2026). https://pith.science/paper/IJCLD4M2
@misc{pith2026260705749,
author = {Pith},
title = {Pith review of: Towards joint optimization of stellarator coils and support structures},
year = {2026},
howpublished = {\url{https://pith.science/paper/IJCLD4M2}},
note = {Machine review of arXiv:2607.05749}
}
read the original abstract
The support structure is an integral part of the design of nuclear fusion reactors, especially 3D stellarator devices. A practical reactor's coils and support structures must have three competing qualities: an accurate magnetic field for good confinement, sufficient rigidity to protect the brittle high-temperature superconductor (HTS) from damage, and a simple geometry for low-cost construction. In existing devices, the coil geometry is often optimized without knowledge of the support structures' design and the coils' true stress and deformation. The support structures are then placed by hand through repeated finite element analyses (FEA) until engineering requirements are met. This makes the structural design of stellarator coil systems lengthy and labor-intensive. Using new developments in differentiable structural mechanics, we present coil-fem, an open-source software tool that integrates support differentiable FEA into the stellarator coil optimization loop. It enables the integrated optimization of coil geometry and support clamp locations to simultaneously reduce magnetic field errors and stresses in the coil body. We also present the first combined coil-support optimization in the stellarator literature. Using a penalty term based on coil-fem, we produced a coil set with 2.4x lower RMS von Mises stress and similar field error compared to an unoptimized baseline.
Figures
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Reference graph
Works this paper leans on
-
[1]
Overview of Disruptions with JET-ILW
S.N. Gerasimov, P. Abreu, G. Artaserse, et al. “Overview of Disruptions with JET-ILW”. In:Nuclear Fusion 60.6 (June 2020), p. 066028.ISSN: 0029-5515, 1741-4326.DOI: 10.1088/1741-4326/ab87b0.URL: https: //iopscience.iop.org/article/10.1088/1741-4326/ab87b0(visited on 02/16/2021)
-
[2]
Significance of MHD Effects in Stellarator Confinement
A. Weller, S. Sakakibara, K. Y . Watanabe, et al. “Significance of MHD Effects in Stellarator Confinement”. In:Fusion Science and Technology50.2 (2006), pp. 158–170.DOI: 10.13182/FST06-A1231. eprint: https: //doi.org/10.13182/FST06-A1231.URL:https://doi.org/10.13182/FST06-A1231
-
[3]
Prospects for pilot plants based on the tokamak, spherical tokamak and stellarator
J.E. Menard, L. Bromberg, T. Brown, et al. “Prospects for pilot plants based on the tokamak, spherical tokamak and stellarator”. In:Nuclear Fusion51.10 (Aug. 2011), p. 103014.DOI: 10.1088/0029-5515/51/10/103014. URL:https://dx.doi.org/10.1088/0029-5515/51/10/103014
-
[4]
Engineering cost & schedule lessons learned on NCSX
R L Strykowsky, T Brown, J Chrzanowski, et al. “Engineering cost & schedule lessons learned on NCSX”. In: 2009 23rd IEEE/NPSS Symposium on Fusion Engineering. San Diego, CA, USA: IEEE, June 2009
work page 2009
-
[5]
ARIES-CS magnet conductor and structure evaluation
X R Wang, A R Raffray, L Bromberg, et al. “ARIES-CS magnet conductor and structure evaluation”. en. In: Fusion Sci. Technol.54.3 (Oct. 2008), pp. 818–837
work page 2008
-
[6]
ARIES-CS coil structure advanced fabrication approach
Lester M Waganer, Kevin T Slattery, John C Waldrop III, et al. “ARIES-CS coil structure advanced fabrication approach”. en. In:Fusion Sci. Technol.54.3 (Oct. 2008), pp. 878–889. 11
work page 2008
-
[7]
Design and test of the support elements of the W7-X magnet system
C Damiani, Maurizio Gasparotto, Bert Giesen, et al. “Design and test of the support elements of the W7-X magnet system”. In:21st IEEE/NPS Symposium on Fusion Engineering SOFE 05. Knoxville, TN: IEEE, Sept. 2005
work page 2005
-
[8]
Hiroyuki Tanoue, Sho Nakagawa, Kazuki Nagahara, et al. “Engineering design and manufacturing of the modular coil system for the quasi-axisymmetric stellarator CFQS-T”. en. In:Fusion Eng. Des.212.114853 (Mar. 2025), p. 114853
work page 2025
Show all 51 references
-
[9]
Preliminary design and analysis of the CFQS supporting structure
Guozhen Xiong, Yuhong Xu, Akihiro Shimizu, et al. “Preliminary design and analysis of the CFQS supporting structure”. en. In:Fusion Eng. Des.160.112021 (Nov. 2020), p. 112021
2020
-
[10]
Design of the superconducting encircling coils for Helios, the planar coil stellarator
Jamal R Olatunji, Daniel Nash, Danis Fort, et al. “Design of the superconducting encircling coils for Helios, the planar coil stellarator”. en. In:Fusion Eng. Des.230.115894 (Sept. 2026), p. 115894
2026
-
[11]
ParaStell: parametric modeling and neutronics support for stellarator fusion power plants
Connor Moreno, Aaron Bader, and Paul Wilson. “ParaStell: parametric modeling and neutronics support for stellarator fusion power plants”. In:Front. Nucl. Eng.3.1384788 (Apr. 2024)
2024
-
[12]
A novel discontinuous-Galerkin deterministic neutronics model for fusion applications: workflow for stellarator reactor design studies
Timo J Bogaarts and Felix Warmer. “A novel discontinuous-Galerkin deterministic neutronics model for fusion applications: workflow for stellarator reactor design studies”. In:Nucl. Fusion66.4 (Apr. 2026), p. 046020
2026
-
[13]
Bayesian methods for magnetic and mechanical optimization of superconducting magnets for fusion
Sam Packman, Nicolò Riva, and Pablo Rodriguez-Fernandez. “Bayesian methods for magnetic and mechanical optimization of superconducting magnets for fusion”. en. In:J. Fusion Energy44.1 (Mar. 2025)
2025
-
[14]
A proof-of-concept for automated AI-driven stellarator coil optimization with in-the-loop finite-element calculations
Alan A Kaptanoglu and Pedro F Gil. “A proof-of-concept for automated AI-driven stellarator coil optimization with in-the-loop finite-element calculations”. In: (Mar. 2026). arXiv:2603.15240 [physics.plasm-ph]
2026
-
[15]
Efficient calculation of self magnetic field, self-force, and self-inductance for electromagnetic coils with rectangular cross-section
Matt Landreman, Siena Hurwitz, and Thomas M Antonsen. “Efficient calculation of self magnetic field, self-force, and self-inductance for electromagnetic coils with rectangular cross-section”. In:Nucl. Fusion65.3 (Mar. 2025), p. 036008
2025
-
[16]
Strain optimisation for ReBCO high-temperature superconducting stellarator coils in SIMSOPT
Paul Huslage, Elizabeth J Paul, Mohammed Haque, et al. “Strain optimisation for ReBCO high-temperature superconducting stellarator coils in SIMSOPT”. en. In:J. Plasma Phys.91.2 (Apr. 2025)
2025
-
[17]
Reactor-scale stellarators with force and torque minimized dipole coils
Alan A Kaptanoglu, Alexander Wiedman, Jacob Halpern, et al. “Reactor-scale stellarators with force and torque minimized dipole coils”. In:Nucl. Fusion65.4 (Apr. 2025), p. 046029
2025
-
[19]
A non-planar ReBCO test coil with 3D-printed aluminum support structure for the EPOS stellarator
Paul Huslage, Tristan Schuler, Pedro F Gil, et al. “A non-planar ReBCO test coil with 3D-printed aluminum support structure for the EPOS stellarator”. In:IEEE Trans. Appl. Supercond.36.3 (May 2026), pp. 1–5
2026
-
[20]
Experimental results from early nonplanar NI-HTS magnet prototypes for the Columbia stellarator eXperiment (CSX)
D Schmeling, M Russo, B T Gebreamlak, et al. “Experimental results from early nonplanar NI-HTS magnet prototypes for the Columbia stellarator eXperiment (CSX)”. In:IEEE Trans. Plasma Sci. IEEE Nucl. Plasma Sci. Soc.(2026), pp. 1–6
2026
-
[21]
https://github.com/johnviljoen/ spineax
Lanke Fu.coil-fem: A differentiable FEA toolkit for stellarator coils. https://github.com/johnviljoen/ spineax. GitHub repository, MIT License. 2026
2026
-
[22]
JAX-FEM: A differentiable GPU-accelerated 3D finite element solver for automatic inverse design and mechanistic data science
Tianju Xue, Shuheng Liao, Zhengtao Gan, et al. “JAX-FEM: A differentiable GPU-accelerated 3D finite element solver for automatic inverse design and mechanistic data science”. In:Computer Physics Communications(2023), p. 108802
2023
-
[23]
Introduction to Finite Element Methods
Carlos A. Felippa. “Introduction to Finite Element Methods”. In: Lecture notes, Aerospace Engineering Sciences. University of Colorado, Boulder, CO, 2004. Chap. 13
2004
-
[24]
Stress singularities in classical elasticity–I: Removal, interpretation, and analysis
G B Sinclair. “Stress singularities in classical elasticity–I: Removal, interpretation, and analysis”. en. In:Appl. Mech. Rev.57.4 (July 2004), pp. 251–298
2004
-
[25]
Society for Industrial and Applied Mathematics, Jan
Pierre Grisvard.Elliptic Problems in Nonsmooth Domains. Society for Industrial and Applied Mathematics, Jan. 2011
2011
-
[26]
Robert D Cook, David S Malkus, Michael E Plesha, et al.Concepts and applications of finite element analysis. en. 4th ed. Nashville, TN: John Wiley & Sons, Oct. 2001
2001
-
[27]
O. C. Zienkiewicz, R. L. Taylor, and J. Z. Zhu.The Finite Element Method: Its Basis and Fundamentals. 7th. Oxford: Butterworth-Heinemann, 2013.ISBN: 978-1-85617-633-0
2013
-
[28]
VIPER: an industrially scalable high-current high-temperature superconductor cable
Zachary Seth Hartwig, Rui F. Vieira, Brandon N. Sorbom, et al. “VIPER: an industrially scalable high-current high-temperature superconductor cable”. en. In:Prof. Hartwig(Oct. 2020).ISSN: 1361-6668.URL: https: //dspace.mit.edu/handle/1721.1/133134(visited on 04/28/2026)
2020
-
[29]
Computation of rotation minimizing frames
Wenping Wang, Bert Jüttler, Dayue Zheng, et al. “Computation of rotation minimizing frames”. en. In:ACM Trans. Graph.27.1 (Mar. 2008), pp. 1–18
2008
-
[30]
Design and construction of coil supporting structure and cryostat vessel for LHD
H Tamura, A Nishimura, S Imagawa, et al. “Design and construction of coil supporting structure and cryostat vessel for LHD”. In:Advances in cryogenic engineering. Springer, 1998, pp. 253–260. 12
1998
-
[31]
Modular coil design developments for the National Compact Stellarator Experiment (NCSX)
D Williamson, A Brooks, T Brown, et al. “Modular coil design developments for the National Compact Stellarator Experiment (NCSX)”. en. In:Fusion Eng. Des.75-79 (Nov. 2005), pp. 71–74
2005
-
[32]
The helically symmetric experiment, (HSX) goals, design and status
F Simon B Anderson, Abdulgader F Almagri, David T Anderson, et al. “The helically symmetric experiment, (HSX) goals, design and status”. en. In:Fusion Technol.27.3T (Apr. 1995), pp. 273–277
1995
-
[33]
Engineering challenges on the low-aspect-ratio quasi-axisymmetric stellarator CFQS-T and its upgrade status toward the 1 T operation
Hiroyuki Tanoue. “Engineering challenges on the low-aspect-ratio quasi-axisymmetric stellarator CFQS-T and its upgrade status toward the 1 T operation”. In:Proceedings of the 25th International Stellarator-Heliotron Workshop (ISHW-2026). National Institute for Fusion Science (...
2026
-
[34]
Stochastic anda posteriorioptimization to mitigate coil manufacturing errors in stellarator design
Florian Wechsung, Andrew Giuliani, Matt Landreman, et al. “Stochastic anda posteriorioptimization to mitigate coil manufacturing errors in stellarator design”. In:Plasma Phys. Control. Fusion64.10 (Oct. 2022), p. 105021
2022
-
[35]
Williamson.NCSX Modular Coils Failure Mode and Effect Analysis (FMEA)
D. Williamson.NCSX Modular Coils Failure Mode and Effect Analysis (FMEA). Tech. rep. NCSX-FMEA- 140-02-00. Prepared by D. Williamson (WBS 14 Manager); Checked by M. Cole (WBS 1/Design Integration Manager); Approved by P. Heitzenroeder (Engineering Manager). Princeton, NJ: Prin...
2008
-
[36]
Design and construction of WENDELSTEIN 7-X
M Wanner, J-H Feist, H Renner, et al. “Design and construction of WENDELSTEIN 7-X”. en. In:Fusion Eng. Des.56-57 (Oct. 2001), pp. 155–162
2001
-
[37]
Mechanical design and construction qualification program on ITER correction coils structures
A Foussat, Wu Weiyue, Wei Jing, et al. “Mechanical design and construction qualification program on ITER correction coils structures”. en. In:Nucl. Eng. Des.269 (Apr. 2014), pp. 116–124
2014
-
[38]
DOLFINx: the next generation FEniCS problem solving environment
Igor A. Baratta, Joseph P. Dean, Jørgen S. Dokken, et al. “DOLFINx: the next generation FEniCS problem solving environment”. In:preprint(2023).DOI:10.5281/zenodo.10447666
2023 doi
-
[39]
Adams, et al.PETSc Web page.http://www.mcs.anl.gov/petsc
Satish Balay, Shrirang Abhyankar, Mark F. Adams, et al.PETSc Web page.http://www.mcs.anl.gov/petsc. 2015.URL:http://www.mcs.anl.gov/petsc
2015
-
[40]
https: //developer.nvidia.com/cudss
NVIDIA Corporation.NVIDIA cuDSS: A High-Performance CUDA Library for Direct Sparse Solvers. https: //developer.nvidia.com/cudss . Version 0.7.0. Documentation: https://docs.nvidia.com/cuda/ cudss/. 2025
2025
-
[41]
https://github.com/johnviljoen/spineax
John Viljoen.Spineax: Sparse Linear Solvers in JAX. https://github.com/johnviljoen/spineax. GitHub repository, MIT License. 2025
2025
-
[42]
New method to design stellarator coils without the winding surface
Caoxiang Zhu, Stuart R Hudson, Yuntao Song, et al. “New method to design stellarator coils without the winding surface”. In:Nucl. Fusion58.1 (Jan. 2018), p. 016008
2018
-
[43]
Augmented Lagrangian methods produce cutting-edge magnetic coils for stellarator fusion reactors
Pedro F Gil, Weiping Li, Julianne Stratton, et al. “Augmented Lagrangian methods produce cutting-edge magnetic coils for stellarator fusion reactors”. In: (July 2025). arXiv:2507.12681 [physics.plasm-ph]
2025 arXiv
-
[44]
Automated optimization of stellarator coils
Michael Drevlak. “Automated optimization of stellarator coils”. en. In:Fusion Technol.33.2 (Mar. 1998), pp. 106–117
1998
-
[45]
W7- X VMEC equilibrium database, configuration 1000_1000_1000_1000_+0000_+0000/01/00jh_l; β= 0 , zero net toroidal current
Joachim Geiger.Wendelstein 7-X Standard Configuration (EIM) Free-Boundary VMEC Equilibrium. W7- X VMEC equilibrium database, configuration 1000_1000_1000_1000_+0000_+0000/01/00jh_l; β= 0 , zero net toroidal current. Max Planck Institute for Plasma Physics (IPP), Greifswald. 20...
2018
-
[46]
Stellarator optimization for good magnetic surfaces at the same time as quasisymmetry
Matt Landreman, Bharat Medasani, and Caoxiang Zhu. “Stellarator optimization for good magnetic surfaces at the same time as quasisymmetry”. en. In:Phys. Plasmas28.9 (Sept. 2021), p. 092505
2021
-
[47]
SIMSOPT: A flexible framework for stellarator optimization
Matt Landreman, Bharat Medasani, Florian Wechsung, et al. “SIMSOPT: A flexible framework for stellarator optimization”. In:J. Open Source Softw.6.65 (Sept. 2021), p. 3525
2021
-
[48]
SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python
Pauli Virtanen, Ralf Gommers, Travis E. Oliphant, et al. “SciPy 1.0: Fundamental Algorithms for Scientific Computing in Python”. In:Nature Methods17 (2020), pp. 261–272.DOI:10.1038/s41592-019-0686-2
2020 doi
-
[49]
Proof of concept of a fast surrogate model of the VMEC code via neural networks in Wendelstein 7-X scenarios
Andrea Merlo, Daniel Böckenhoff, Jonathan Schilling, et al. “Proof of concept of a fast surrogate model of the VMEC code via neural networks in Wendelstein 7-X scenarios”. In:Nucl. Fusion61.9 (Sept. 2021), p. 096039
2021
-
[50]
Stellarator design exploration using symbolic- regression neutronics surrogates
Enrique Miralles-Dolz, Michael Churchill, Jacob Schwartz, et al. “Stellarator design exploration using symbolic- regression neutronics surrogates”. In:IEEE Trans. Plasma Sci. IEEE Nucl. Plasma Sci. Soc.54.6 (June 2026), pp. 2879–2886
2026
-
[51]
Low-dimensional geometry learning for turbulence prediction in optimized stellarators
Xishuo Wei, Handi Huang, Haotian Chen, et al. “Low-dimensional geometry learning for turbulence prediction in optimized stellarators”. In: (Mar. 2026). arXiv:2603.17366 [physics.plasm-ph]
2026 arXiv
-
[52]
Fu Lanke.Coil-fem Validation Dataset. 2026. 13
2026
Reviewed July 11, 2026 · model on record in the stance chip above.
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