On the merit of hot ion mode for tearing mode stabilization

TL;DR

This paper explores how hot ion mode enhances the rf current condensation effect, significantly improving the passive stabilization of tearing modes in magnetic confinement devices.

Contribution

It demonstrates that hot ion mode can dramatically amplify the self-healing rf current condensation effect, enabling more effective passive tearing mode stabilization.

Findings

Hot ion mode increases electron temperature, boosting current condensation.

Enhanced stabilization of tearing modes with broad rf profiles.

Potential for improved steady-state plasma confinement.

Abstract

The stabilization of tearing modes with rf driven current benefits from the cooperative feedback loop between rf power deposition and electron temperature within the island. This effect, termed rf current condensation, can greatly enhance and localize current driven within magnetic islands. It has previously been shown that the condensation effect opens the possibility of passive stabilization with broad rf profiles, as would be typical of LHCD for steady state operation. Here we show that this self-healing effect can be dramatically amplified by operation in a hot ion mode, due to the additional electron heat source provided by the hotter ions.