On the role of filaments in perpendicular heat transport at the Scrape-off Layer

Abstract

In this work we carry out quantitative measurements of particle and heat transport associated to SOL filaments in a tokamak, and relate density shoulder formation to the advection of energy in the far SOL. For the first time, this attempt includes direct measurements of ion and electron temperatures for background and filaments. With this aim, we combine data from a number of equivalent L-mode discharges from the ASDEX Upgrade tokamak in which different probe heads were installed on the midplane manipulator. This approach is validated by a comparison with independent diagnostics. Results indicate an increase of heat transport associated to filaments after the shoulder formation. Several centimeters into the SOL, filaments are still found to carry a substantial fraction (up to one fifth) of the power ejected at the separatrix.

arXiv commentPublished in Nucler Fusion

References in corpus (5)

• An experimental investigation on the high density transition of the Scrape-off Layer transport in ASDEX Upgrade
• Experimental validation of a filament transport model in turbulent magnetized plasmas
• Recent progress towards a quantitative description of filamentary SOL transport
• Influence of temperature fluctuations on plasma turbulence investigations with Langmuir probes
• Scrape-off layer ion temperature measurements at the divertor target during type III and type I ELMs in MAST measured by RFEA

Cited by in corpus (4)

• Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges
• X-point and divertor filament dynamics from Gas Puff Imaging on TCV
• A hybrid full-wave Markov chain approach to calculating radio-frequency wave scattering from Scrape-off Layer filaments
• Dynamics of scrape-off layer filaments in detached conditions