Pedestal instabilities during the L-H transition in ASDEX-Upgrade plasmas

The high confinement regime, or H-mode, is the result of a transport barrier at the plasma edge, where the pressure rises sharply to form a pedestal. This paper reports on a collection of experimental observations of instabilities and turbulence occurring in this decisive and narrow edge region. Using the high sampling rate enabled by an ultra-fast frequency sweeping reflectometer, a high spatial and temporal resolution analysis of density, gradients, and turbulence allows new and thorough insights on plasma instabilities arising from the microturbulence and flow competing system during the I-phase to the edge localized modes and blob-filaments during the established H-mode. The measurements provide the observation on how different instabilities can arise in the pedestal during the L-H transition and address their specific turbulent natures.

F Clairet, Anna Medvedeva, G D Conway, C Bottereau. Pedestal instabilities during the L-H transition in ASDEX-Upgrade plasmas. Plasma Physics and Controlled Fusion, 2025, 67 (3), pp.035030. ⟨10.1088/1361-6587/adb887⟩. ⟨hal-05404569⟩

Journal: Plasma Physics and Controlled Fusion

Date de publication: 03-03-2025

Auteurs:
  • F Clairet
  • Anna Medvedeva
  • G D Conway
  • C Bottereau

Digital object identifier (doi): http://dx.doi.org/10.1088/1361-6587/adb887


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