Article
Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas
Author/s | Balestri, A.
Ball, Juliane Coda, S. Cruz Zabala, Diego José García Muñoz, Manuel Viezzer, Eleonora |
Department | Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear |
Publication Date | 2024-05-30 |
Deposit Date | 2024-07-18 |
Published in |
|
Abstract | In this work, we study the impact of aspect ratio A = R 0 / r (the ratio of major radius R 0 to minor radius r) on the confinement benefits of negative triangularity (NT) plasma shaping. We use high-fidelity flux tube ... In this work, we study the impact of aspect ratio A = R 0 / r (the ratio of major radius R 0 to minor radius r) on the confinement benefits of negative triangularity (NT) plasma shaping. We use high-fidelity flux tube gyrokinetic GENE simulations and consider several different scenarios: four of them inspired by TCV experimental data, a scenario inspired by DIII-D experimental data and a scenario expected in the new SMART spherical tokamak. The present study reveals a distinct and non-trivial dependence. NT improves confinement at any value of A for ITG turbulence, while for TEM turbulence confinement is improved only in the case of large and conventional aspect ratios. Additionally, through a detailed study of a large aspect ratio case with pure ITG drive, we develop an intuitive physical picture that explains the beneficial effect of NT at large and conventional aspect ratios. This picture does not hold in TEM-dominated regimes, where a complex synergistic effect of many factors is found. Finally, we performed the first linear gyrokinetic simulations of SMART, finding that both NT and PT scenarios are dominated by micro-tearing-mode (MTM) turbulence and that NT is more susceptible to MTMs at tight aspect ratio. However, a regime where ITG dominates can be found in SMART, and in this regime NT is more linearly stable. |
Funding agencies | EUROfusion Consortium |
Project ID. | 101052200 |
Citation | Balestri, A., Ball, J., Coda, S., Cruz Zabala, D.J., García Muñoz, M. y Viezzer, E. (2024). Physical insights from the aspect ratio dependence of turbulence in negative triangularity plasmas. Plasma Physics and Controlled Fusion, 66 (7), 075012. https://doi.org/10.1088/1361-6587/ad4d1d. |
Files | Size | Format | View | Description |
---|---|---|---|---|
Physical insights.pdf | 2.254Mb | [PDF] | View/ | Versión publicada |