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On TCV and DIII-D, negative-triangularity (NT) plasmas have demonstrated good, reactor-relevant energy confinement while remaining in L-mode, thereby avoiding major H-mode power-exhaust issues such as ELMs and the L–H power threshold. On TCV, Ohmic studies found that NT plasmas were harder to detach than similar positive-triangularity (PT) plasmas [1], ascribed, in part, to a lower scrape-off layer (SOL) width [2]. NT Ohmic experiments on the same machine also showed that Alternative Divertor Configurations (ADCs) enhanced detachment processes, particularly with the formation of an X-point radiator [3]. Detachment of all targets was achieved at core line-averaged densities, where, with a conventional divertor, only outer target cooling is observed. In this contribution, we extend the NT power exhaust studies to integrated scenarios with auxiliary heating, closer to being reactor-relevant, focusing on divertor-core coupling. Specifically, this work focuses on the Snowflake (SF), a divertor with a secondary X-point and the X-divertor (XD), which has increased poloidal flux expansion. The combination of ADCs and negative non-X-point triangularity (δNXP) led to a L-mode scenario at high input power featuring H-mode-like performance (H98>1) together with a detached divertor. At δNXP~-0.3, an SF scenario with 550 kW of NBI heating and an average core density of 4.5×10^19 m-3 (fG ~0.4) has been developed. In stationary conditions, βN ≈ 1.6 and H98 reaches 1.4, approximately 10% higher than a TCV positive triangularity (PT) H-mode reference with 1.3MW NBI. Nitrogen seeding led to the formation of an X-point radiator and to the detachment of the outer targets. At similar core-performances, the NBI-heated PT ELMy H-mode achieved detachment only between ELM burn-throughs. In the NT-SF scenario, seeding reduced the core performances (H98 and βN) by ~10%, correlated with core dilution, with Zeff increasing from 2 to 2.4. In comparison, the PT reference scenario’s performances are affected by ~15%. Further use of beta-control allowed for mitigating the effect of seeding on the core performances while maintaining a detached divertor. Experimental insights of these findings, enabled by TCV's extensive diagnostic coverage, are presented, contributing to understanding the conditions in which NT can be detached with a reactor-relevant core.
[1] O Février et al 2024 Plasma Phys.Control.Fusion 66 065005
[2] R. Morgan et al 2025 Nucl.Fusion 65 106030
[3] G. Durr-Legoupil-Nicoud et al, in prep