Negative triangularity scenarios: from TCV and AUG experiments to DTT predictions
Experiments, gyrokinetic simulations and transport predictions were performed to investigate if a negative triangularity (NT) L-mode option for the Divertor Tokamak Test (DTT) full-power scenario would perform similarly to the positive triangularity (PT) H-mode reference scenario, avoiding the harmful edge localized modes (ELMs). The simulations show that a beneficial effect of NT coming from the edge/scrape-off layer (SOL) region ρ tor > 0.9 is needed to allow the actual NT L-mode option to perform like the PT H-mode. Dedicated experiments at TCV and AUG, with DTT-like shapes, show an optimistic picture. In TCV, experiments indicate that even with the relatively small triangularity of the DTT NT scenario, a large beneficial effect of NT comes from the plasma edge and SOL, allowing NT L-modes to outperform PT L-modes with the same power input, reaching the same central pressures as PT H-modes with twice as much applied heating power. For AUG, NT plasmas go into H-mode more easily than for TCV, but always present much smaller pedestals compared with PT plasmas with the same input power, showing a much weaker or absent ELM activity. However, NT has a smaller beneficial effect for AUG than for TCV, with NT pulses outperforming PT pulses with the same input power only for an ECRH-only case with relatively low input power. For the considered AUG cases, PT pulses perform better than NT ones at higher ECRH power or with mixed NBI and ECRH power. Based on this analysis, the NT option is a viable alternative for the DTT full power scenario, providing high performance plasmas with reduced or absent ELMs.
2-s2.0-85202450909
Consiglio Nazionale delle Ricerche
Università degli Studi di Milano-Bicocca
École Polytechnique Fédérale de Lausanne
Consiglio Nazionale delle Ricerche
The University of Texas at Austin
Università degli Studi di Napoli Federico II
École Polytechnique Fédérale de Lausanne
Università degli Studi della Tuscia Viterbo
École Polytechnique Fédérale de Lausanne
Università degli Studi di Padova
2024-10-01
64
10
106024
REVIEWED
EPFL
Funder | Funding(s) | Grant Number | Grant URL |
European Commission or SERI | |||
SERI | |||
CINECA | |||
Show more |