Enhanced performance in quasi-isodynamic max-$J$ stellarators with a turbulent particle pinch

TL;DR

This paper introduces SQuID-τ, a stellarator design that uses turbulence-induced inward particle transport to sustain density peaks, improving confinement and relaxing design constraints.

Contribution

It presents a novel stellarator configuration capable of self-fueling via turbulence-driven inward particle transport, enhancing performance.

Findings

Gyrokinetic simulations show improved temperature and density profiles.

The design allows for smaller size and weaker magnetic fields in reactors.

Turbulence-induced inward transport enables density peaking without advanced fueling.

Abstract

Recent stellarator reactor designs demonstrate mostly outward turbulent particle transport, which, without advanced fueling technology, inhibits the formation of density gradients needed for confinement. We introduce ``SQuID-$\tau$'', a self-fueling quasi-isodynamic stellarator capable of sustaining density peaking through inward particle transport caused by turbulence. Temperature and density profile predictions based on high-fidelity gyrokinetic simulations demonstrate enhanced performance, significantly relaxing constraints on the size and magnetic field strength for reactor designs.