Experiments and modelling of negative triangularity ASDEX Upgrade plasmas in view of DTT scenarios

• DOI: 10.1088/1361-6587/ad4d1c
• Publication Date: 2024-05-17T22:27:32Z
• Authors: L Aucone; P Mantica; T Happel; J Hobirk; T Pütterich; B Vanovac; C F B Zimmermann; M Bernert; T Bolzonella; M Cavedon; M Dunne; R Fischer; P Innocente; A Kappatou; R M McDermott; A Mariani; P Muscente; U Plank; F Sciortino; G Tardini; the EUROfusion WP...; the ASDEX Upgrade...
• Keywords: ASDEX Upgrade; Upgrade

Abstract The paper presents experimental and modelling results of a comparison negative (NT) positive (PT) triangularity ASDEX Upgrade (AUG) discharges using the plasma shapes presently foreseen in DTT tokamak, under construction Italy. This work is part broader effort investigation to understand whether good properties observed NT scenarios DIII-D TCV may be extrapolated device more generally DEMO future operations. have shown practical gain running these AUG plasmas with only ECRH mixed NBI+ECRH phases triangularity, even if they access H-mode. Indeed, electron kinetic profiles recover all cases PT pressures inside mid-radius due reduced transport region <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>ρ</mml:mi> <mml:mtext>tor</mml:mtext> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>0.7</mml:mn> <mml:mo>−</mml:mo> <mml:mn>0.9</mml:mn> </mml:mrow> </mml:math> , while exhibiting lower individual ELM (Edge Localised Mode) energy losses. ion pressure expected fusion performance are comparable case similar densities. Integrated has been performed solver ASTRA quasi-linear turbulent model TGLF, investigating discharges. reproduces experiments qualitatively reasonable accuracy. Nonetheless, heat partially overestimated. because TGLF uses Miller equilibrium, which approximates magnetic flux surfaces as up-down symmetric. In caseof asymmetric shapes, simulated outer lose tilt respect z -axis, reducing upper δ &lt; 0 effect. A numerical test discern impact geometry by symmetrically flipping shape beneficial effect on transport.