Investigation of the sheared flows and staircases with a full-wave 2D synthetic diagnostic FeDoT

Poloidal flows and avalanches play a key role in tokamak plasma self-organization by suppressing turbulence in sheared flow regions, contributing to the formation of weak transport barriers. These structures, predicted by GYSELA simulations and indirectly observed in the Tore Supra tokamak, are challenging to detect due to their millimeter-scale size. This study uses the ultra-fast-swept reflectometer (UFSR), capable of high spatial resolution and signal-to-noise ratio, to analyze turbulence characteristics, including flow-induced spectral asymmetries.The synthetic diagnostic FeDoT, developed for UFSR data interpretation, enables the study of these structures using 2D wave propagation simulations and advanced signal processing routines. FeDoT simulations demonstrate that the coherence length, derived from reflectometer signals, closely aligns with the radial structure of the radial electric field and can be used to detect staircases. Furthermore, spectral asymmetry, indicative of flow direction and sheared flows, is quantified using a novel spectral chirality metric. These findings validate the use of reflectometry for detecting flows and transport barriers, providing insights into the interplay between turbulence and transport.