arXiv subjects

Eve V. Stenson

Publications and source records attributed to Eve V. Stenson.

4 recordsLinked to original sources

arXiv2026

Efficient Computation of Stellarator Coils with an Augmented Lagrangian Optimization Method

Finding feasible coils for stellarator fusion devices is a critical challenge of realizing this concept for future power plants. Current design efforts struggle to navigate the highly nonconvex optimization landscape, spend considerable resources scanning the parameter space, and may produce suboptimal coils. In this work, we present an augmented Lagrangian approach to tackle the ill-posed problem of coil optimization. We illustrate its effectiveness and versatility by generating coils for five stellarators with very different symmetries and magnetic field shaping. In all cases, we find Pareto-optimal coil solutions that in various ways outperform published coil sets.

physics.plasm-ph↗

arXiv2026

Stochastic single-stage stellarator optimization using fixed-boundary equilibria

In this paper, single-stage stellarator optimization is combined with stochastic coil optimization to improve the robustness of the stellarator as compared to deterministic methods. The plasma boundary, solved with an MHD solver in fixed-boundary mode, is linked to a set of randomly perturbed coils via the squared flux. The optimizer avoids sharp local minima and can reach improved configurations. Two different configurations obtained with our method, one quasi-axisymmetric and one quasi-helically symmetric, are compared against both the standard stochastic stage II method and the single-stage method. The new configurations shown here yield improved squared flux, quasisymmetry, and particle loss following a posteriori perturbation of the coils.

physics.plasm-ph↗

arXiv2026

Designing A Buildable Optimized Stellarator to Confine Electron-Positron Plasmas

In this paper, the design of the the plasma equilibrium and superconducting coils for the Electrons and Positrons in an Optimized Stellarator EPOS experiment is presented. With newly developed stellarator optimization tools, including single-stage and stochastic optimization, as well as HTS strain, this work demonstrates that it is possible to achieve key metrics for the buildability and confinement properties of the device. In particular, satisfactory quality of quasisymmetry and stellarator robustness is designed, and engineering requirements are met for eight different candidates. A feasibility study is presented that optimizes multiple candidates for different plasma major radii and coil currents, as well as the best EPOS candidate to date.

physics.plasm-ph↗

arXiv2025

A Non-planar ReBCO Test Coil with 3D-printed Aluminum Support Structure for the EPOS Stellarator

We report on the test of a small scale, non-planar coil using non-insulated ReBCO tape wound on a 3D-printed aluminum support structure. A 3D-scan of the winding frame which was printed out of AlSi10Mg using selective laser melting, showed peak manufacturing deviations of 0.3 mm. We tested the coil with 21 turns of 3 mm wide tape cooled both by liquid nitrogen and with a cryocooler. We achieved a central field strength of up to 21 mT which agrees with the prediction suggesting that we manufactured the coil without defects. The peak field was reached at a supply current of 120 A. The current leads showed a contact resistance of $\left(2.25\pm0.13\right)μΩ$. The discharge time $L/R$ was found to be 0.63 s in liquid nitrogen and 2.92 s when cooled by the cryocooler. From this we estimate a winding pack temperature of 41 K.

physics.ins-det↗