Advancing the Concept of the Quasi-isodynamic Stellarator

The success of the Wendelstein-7X experiment places the quasi-isodynamic (QI) stellarator at the forefront of contenders for next-generation stellarator reactor concepts. A compelling new design would merge low neoclassical transport with objectives like fast particle confinement, ease of construction and even low turbulent transport. This talk presents recent theoretical work to support the search for such QI designs. We shed light on the design space of QI stellarators, including the key geometric parameters that define separate previously unknown classes, and unexplored areas of parameter space. Solutions with unexpected properties, like low plasma elongation, field period numbers, aspect ratio, and broken stellarator symmetry, open up new optimization lines to explore.