Turbulent Nature of the Quasicontinuous Exhaust Regime for Fusion Plasmas

Abstract

We demonstrate a turbulence mechanism that reconciles high plasma confinement with efficient heat exhaust -- a central challenge for fusion energy. Global two-fluid turbulence simulations of the reactor-relevant Quasicontinuous Exhaust regime on the ASDEX Upgrade tokamak reveal that a quasicoherent mode drives mesoscopic oscillations of the pedestal boundary across the magnetic separatrix and ejects ballistic filaments (blobs), reproducing both the mean profiles and turbulent fluctuations observed experimentally. This behavior arises from a synergistic interplay between kinetic ballooning modes and resistive X-point modes straddling the separatrix. These first-principles results place extrapolations to future fusion reactors on a firm physical footing.

References in corpus (5)

• Global turbulence simulations of the tokamak edge region with GRILLIX
• A quasi-continuous exhaust scenario for a fusion reactor: the renaissance of small edge localized modes
• MHD simulations of small ELMs at low triangularity in ASDEX Upgrade
• Tokamak edge-SOL turbulence in H-mode conditions simulated with a global, electromagnetic, transcollisional drift-fluid model
• Magnetic flutter effect on validated edge turbulence simulations