Experimental validation of a filament transport model in turbulent magnetized plasmas

Abstract

In a wide variety of natural and laboratory magnetized plasmas, filaments appear as a result of interchange instability. These convective structures substantially enhance transport in the direction perpendicular to the magnetic field. According to filament models, their propagation may follow different regimes depending on the parallel closure of charge conservation. This is of paramount importance in magnetic fusion plasmas, as high collisionality in the scrape-off layer may trigger a regime transition leading to strongly enhanced perpendicular particle fluxes. This work reports for the first time on an experimental verification of this process, linking enhanced transport with a regime transition as predicted by models. Based on these results, a novel scaling for global perpendicular particle transport in reactor relevant tokamaks such as ASDEX-Upgrade and JET is found, leading to important implications for next generation fusion devices.

arXiv commentRegarding JET-EFDA Contributors, see the Appendix of F. Romanelli et al., Proceedings of the 25th IAEA Conference 2014, St Petersburg, Russia. Submitted to Physical Review Letters

References in corpus (3)

• An experimental investigation on the high density transition of the Scrape-off Layer transport in ASDEX Upgrade
• Influence of temperature fluctuations on plasma turbulence investigations with Langmuir probes
• Radial convection of finite ion temperature, high amplitude plasma blobs

Cited by in corpus (15)

• Recent progress towards a quantitative description of filamentary SOL transport
• On the role of filaments in perpendicular heat transport at the Scrape-off Layer
• The influence of temperature dynamics and dynamic finite ion Larmor radius effects on seeded high amplitude plasma blobs
• X-point and divertor filament dynamics from Gas Puff Imaging on TCV
• Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges
• Intermittent fluctuations in the Alcator C-Mod scrape-off layer for ohmic and high confinement mode plasmas
• L-mode filament characteristics on MAST as a function of plasma current measured using visible imaging
• Probability distribution functions for intermittent scrape-off layer plasma fluctuations
• Gyrokinetic treatment of a grazing angle magnetic field
• Unified transport scaling laws for plasma blobs and depletions
• Amplitude and size scaling for interchange motions of plasma filaments
• Characterization of edge and scrape-off layer fluctuations using the fast Li-BES system on COMPASS
• Observation of quasi-coherent density fluctuation in scrape-off layer enhancing boundary transport in high-betaN hybrid plasmas on DIII-D
• Magnetic Fluctuations in Gyrokinetic Simulations of Tokamak Scrape-Off Layer Turbulence
• Sheath constraints on turbulent magnetised plasmas