Continuous observation of filaments from the confined region to the far scrape-off layer

the ASDEX Upgrade Team, the EUROfusion MST1 Team

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

The thermal helium beam diagnostic at ASDEX Upgrade can access the whole plasma edge region simultaneously with a high spatiotemporal resolution. Manifold dynamics of plasma edge transport is observed for different plasma confinement regimes, comprising L- and H-mode scenarios with type-I and small ELMs as well as ELM free EDA regimes. The measurements show that the plasma dynamics in the confined region close to the separatrix is often dominated by regular high frequency modes (10–100 kHz), whereas filaments with an intermittent occurrence rate of 0.1–2 kHz dominate in particular the far scrape-off layer (SOL). The comparison among different regimes shows a similar filamentary activity between L-mode and inter-ELM H-mode phases. An increased filamentary activity in H-mode, however, is found for rising densities n∕nGW. This is the case for the regime of quasi continuous exhaust (QCE) with three times higher filament velocities compared to a clean inter-ELM H-mode.

Original languageEnglish
Article number100854
JournalNuclear Materials and Energy
Volume25
DOIs
StatePublished - Dec 2020

Keywords

  • Confinement regimes
  • Convective transport
  • ELM free regimes
  • Helium beam diagnostic
  • Plasma filaments
  • Quasi-coherent modes
  • Scrape-off layer

Fingerprint

Dive into the research topics of 'Continuous observation of filaments from the confined region to the far scrape-off layer'. Together they form a unique fingerprint.

Cite this