David A. Gates
Stellarator Physics Division Head, Princeton Plasma Physics Laboratory

Title: Stellarator Research Needs for Fusion Energy Development

Abstract: The stellarator offers ready solutions to critical challenges for toroidal confinement fusion: it provides a steady-state, disruption-free reactor concept with minimal power requirements for plasma sustainment. The stellarator concept has undergone a rebirth in recent years as a result of major advances in theoretical understanding, the advent of computational capabilities, and experimental research that have made predictive understanding of many aspects of three dimensional magnetic confinement systems a reality. As a result of these advances stellarators are at the forefront of plasma physics research. The configurational flexibility afforded by the removal of the toroidal symmetry constraint opens up new physics regimes. It allows us to test our understanding of symmetry effects on plasma confinement and to produce the most physics-optimized fusion configuration yet conceived. The US stellarator community proposes to undertake an integrated stellarator initiative to test innovations that can dramatically improve plasma confinement and provide a more robust basis for the development of fusion energy. Optimized designs would combine features of neoclassically optimized high-? concepts with opportunities for new conceptual advances such as:

- Reduction of turbulent transport.
- Use of QS to improve high-energy particle confinement and reduce impurity accumulation.
- Simplified coils/support structures, with reduced non-planar distortion and increased access.
- A robust divertor system that is insensitive to the details of the equilibrium.

A successful optimization and design effort based on the above steps will lead directly to plans for enhanced research facilities.

Host: Francesco Volpe