TJ-II: 2D mapping of plasma potential and density and their fluctuations in ECRH plasmas: Difference between revisions

First 2D poloidal contour plots of plasma potential and density and their fluctuations have been measured in plasmas sustained by ECRH in the TJ-II stellarator <ref> R. Sharma et al., Nuclear Fusion 20199 (submitted)</ref> <ref> A. Melnikov et al., ISHW 2019</ref>. The 2D map for the absolute plasma potential shows a local maximum in the plasma core as expected in electron root scenarios. Density fluctuations appear both at positive and negative density gradient regions, with normalized level of density fluctuations higher in the negative density gradient region. The TJ-II innovative experimental set-up developed using a dual HIBP diagnostic pave the way for model validation on core plasma potential asymmetries and particle transport under positive density gradient scenarios in the TJ-II stellarator.