Simplified and Flexible Coils for Stellarators using Single-Stage Optimization

TL;DR

This paper demonstrates how single-stage optimization can efficiently generate innovative stellarator coil designs, including configurations with minimal coils and combined symmetry properties, streamlining the stellarator design process.

Contribution

It introduces a unified optimization framework that enables rapid discovery of diverse stellarator coil configurations with simplified coil structures.

Findings

New stellarator designs with few coils are achievable.

Configurations with combined quasisymmetries are demonstrated.

Streamlined design process accelerates stellarator development.

Abstract

Single-stage optimization, also known as combined plasma-coil algorithms or direct coil optimization, has recently emerged as a possible method to expedite the design of stellarator devices by including, in a single step, confinement, stability, and engineering constraints. In this work, we show how such frameworks allow us to find new designs in a streamlined manner, yielding a broad range of new configurations. Examples are shown for stellarators with a small number of coils and quasisymmetric stellarators with only one to three coils per half field period, with external trim coils, helical coils, and a single set of coils generating both a quasi-axisymmetric and a quasi-helical equilibrium.