Coil Optimization of Quasi-Symmetric Stellarators

Optimized coil configurations are developed for quasi-symmetric stellarators using the SIMSOPT code [M. Landreman, et al., J. Open Source Software 6, 3525 (2021)]. Recent work has shown that configurations with high degrees of quasi-symmetry and excellent particle confinement can be obtained [M. Landreman and E. Paul, Phys. Rev. Lett. 128, 035001 (2022)]. This work develops coils for some of these configurations including targets appropriate for a reactor-scale device. Both quasi-axisymmetric and quasi-helically symmetric configurations are tested. The deviation from quasi-symmetry obtained with the optimized coil configurations will be analyzed. The effects of different coil configurations on Ideal MHD stability, neoclassical transport and energetic particle confinement will be examined. Further testing will examine optimization with the necessary coil constraints for a fusion reactor [A. Boozer, Phys. Plasmas 31, 060601 (2024)] included in the optimization process.