Divertor closure effects on the TCV boundary plasma

The Tokamak à Configuration Variable (TCV) has recently been equipped with gas baffles to increase its divertor closure for a broad range of magnetic geometries. First experimental results reported in Reimerdes et al. (2021) demonstrated compatibility geometries and confirmed the main design constraints baffles, particular an increased neutral pressure. present article presents more in-depths analysis extended experiments this first baffle assessment on TCV boundary plasma. It is shown that pressure following installation as predicted by SOLPS-ITER SolEdge2D-EIRENE simulations. Varying changing position plasma showed equilibrium designed assess effect was not far from optimal trade-off between plugging recycling baffles. facilitate access partially detached regime both L- H-modes. In L-Mode, ion ?B-drift directed X-Point core, reduction line-averaged density detachment threshold approximately 20% observed at outer target, while inner strike point only achieved presence Multispectral imaging shows CIII front moves target towards lower density, indicating colder leg. H-mode, generally located near ELMs, without N2-seeding required move up location.