Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade

J. Horacek, J. Adamek, H.W. Müller, J. Seidl, Anders Henry Nielsen, V. Rohde, F. Mehlmann, C. Ionita, E. Havlickova

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    This paper focuses on interpretation of fast (1 µs) and local (2–4 mm) measurements of plasma density, potential and electron temperature in the edge plasma of tokamak ASDEX Upgrade. Steady-state radial profiles demonstrate the credibility of the ball-pen probe. We demonstrate that floating potential fluctuations measured by a Langmuir probe are dominated by plasma electron temperature rather than potential. Spatial and temporal scales are found consistent with expectations based on interchange-driven turbulence. Conditionally averaged signals found for both potential and density are also consistent; however, those for temperature show an unexpected ~4 mm wide decrease by 10% at the very centre of a blob. In the wall shadow, temperature measured by the swept Langmuir probe yields values ~10 eV, whilst the ball-pen temperature gradient is more steep and credible, dropping down to ~1 eV.
    Original languageEnglish
    JournalNuclear Fusion
    Volume50
    Issue number10
    Pages (from-to)105001
    ISSN0029-5515
    DOIs
    Publication statusPublished - 2010

    Keywords

    • Fusion energy

    Cite this

    Horacek, J., Adamek, J., Müller, H. W., Seidl, J., Nielsen, A. H., Rohde, V., Mehlmann, F., Ionita, C., & Havlickova, E. (2010). Interpretation of fast measurements of plasma potential, temperature and density in SOL of ASDEX Upgrade. Nuclear Fusion, 50(10), 105001. https://doi.org/10.1088/0029-5515/50/10/105001