2025/04/07 by C. Killer, Carsten Killer, D. Cipciar +12 · 1 citation
Physics and Astronomy · #Magnetic confinement fusion research #Solar and Space Plasma Dynamics #Ionosphere and magnetosphere dynamics
paper · doi:10.1088/1741-4326/adc9c0
Abstract In the island divertor scrape-off layer (SOL) of the Wendelstein 7-X stellarator, 2D-resolved Langmuir probe measurements uncover a complex spatial structure of electron temperature, density, and floating potential. Depending on details of magnetic island size and position, significant poloidal gradients and non-monotonic radial profiles are observed. The resulting electric fields imply the presence of sheared stationary drift flows with poloidal velocities of a few km s −1 , with flow channels as narrow as one cm. Such flows are observed with a gas puff imaging diagnostic in qualitative agreement with the probe results and imply a significant transport channel in the SOL. The 2D distribution of plasma parameters is intricately associated with the unique magnetic structure of the island divertor SOL and highlights the necessity for more accurate magnetic field reconstructions.