Physics Optimization for a New UW-Madison Mid-Scale Quasi-Helically Symmetric Stellarator*

A new mid-scale quasi-helically symmetric (QHS) stellarator should be designed and built as soon as possible to realize the potential of QHS configurations for fusion energy. New advancements in stellarator design greatly improve optimization pathways. In this poster we describe novel metrics for stellarator optimization and present their effects on stellarator design. Design considerations include: turbulent optimization, specifically by maximizing coupling from unstable to stable modes; simplified coil design and plasma boundaries conducive to simpler coils; self-consistent bootstrap current calculations; divertor solutions capable of operating over a range of plasma current; and improvements to energetic particle confinement. Incorporating these elements into a design will lead to a US experimental facility capable of significantly advancing the stellarator concept.