Critical gradient turbulence optimization toward a compact stellarator reactor concept

TL;DR

This paper presents a novel stellarator design optimized for reduced turbulence and heat flux, combining favorable confinement properties with simplified coil configurations for potential reactor applications.

Contribution

It introduces a turbulence-aware optimization approach that yields a compact, stable, and efficient stellarator configuration with simplified coils and improved confinement.

Findings

Significantly reduced turbulent heat fluxes compared to existing stellarators.

Achieves low neoclassical transport and good alpha particle confinement.

Maintains Mercier stability at high plasma beta (~2%).

Abstract

Integrating turbulence into stellarator optimization is shown by targeting the onset for the ion-temperature-gradient mode, highlighting effects of parallel connection length, local magnetic shear, and flux surface expansion. The result is a compact quasihelically symmetric stellarator configuration, admitting a set of uncomplicated coils, with significantly reduced turbulent heat fluxes compared to a known stellarator. The new configuration combines low values of neoclassical transport, good alpha particle confinement, and Mercier stability at a plasma beta of almost 2$\%$.