Coda, S.Merle, A.Sauter, O.Porte, L.Bagnato, F.Boedo, J.Bolzonella, T.Fevrier, O.Labit, B.Marinoni, A.Pau, A.Pigatto, L.Sheikh, U.Tsui, C.Vallar, M.Vu, T.2022-01-312022-01-312022-01-312022-01-0110.1088/1361-6587/ac3fechttps://infoscience.epfl.ch/handle/20.500.14299/184990WOS:000729981500001The favorable confinement properties of negative-triangularity (NT) tokamak configurations were discovered in the TCV tokamak in the late 1990s and were documented over the two following decades, through investigations of predominantly electron-heated plasmas in limited topologies. The most recent experimental campaign in TCV has marked a leap forward, characterized by the development of a variety of diverted NT shapes that are robustly stable with basic Ohmic heating. The application of auxiliary heating, directed now at both electrons and ions (using electron-cyclotron resonance heating as well as neutral-beam injection), has enabled the achievement of record performances for L-mode plasmas, with normalized beta values reaching 2.8 transiently (as well as 2 in steady state, but reverting to a limited configuration) and with comparable ion and electron temperatures. The systematic confinement enhancement with NT is confirmed in these experiments. The L-mode existence space is broader than at positive triangularity, with only sporadic transitions to H-mode observed up to 1.4 MW heating power regardless of the magnetic-field-gradient direction relative to the X-point. These experiments are planned to be continued with even higher power following a heating-source upgrade.Physics, Fluids & PlasmasPhysicsplasmanuclear fusiontokamaktcvtriangularityconfinementstabilitytransportshapetext::journal::journal article::research article