Multi-objective stellarator optimization studies

The realization of stellarator fusion power plants relies on the use of optimization techniques to provide 3-D magnetic field configurations with excellent plasma confinement properties. Optimization activities are reported in targeted areas of plasma physics dedicated to improving the stellarator concept. In this work, both quasi-isodynamic (QI) and quasi-symmetric (QS) configurations are considered. An emerging area of emphasis is the need to improve the turbulent transport properties of stellarators. Optimization schemes are developed using reduced models to monitor the efficacy of turbulent transport reduction. Configurations produced through optimization using reduced models for turbulent transport are assessed using gyrokinetic based transport modeling. Turbulent improved configurations are sought consistent with excellent neoclassical and energetic particle transport, self-consistent bootstrap current, robust MHD equilibrium, local and global MHD stability and simplified coil design. Consistency of these designs with scalable divertor solutions are also addressed.