Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges

0544085 - ÚFP 2022 RIV AT eng J - Journal Article
Giacomin, M. - Stagni, R. - Ricci, P. - Boedo, J. A. - Horáček, Jan - Reimerdes, H. - Tsui, C.K.
Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges.
Nuclear Fusion. Roč. 61, č. 7 (2021), č. článku 076002. ISSN 0029-5515. E-ISSN 1741-4326
R&D Projects: GA ČR(CZ) GA20-28161S; GA MŠMT(CZ) EF16_013/0001551
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : gbs * plasma turbulence * scrape-off layer width
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 4.215, year: 2021
Method of publishing: Limited access
https://iopscience.iop.org/article/10.1088/1741-4326/abf8f6

Theory-based scaling laws of the near and far scrape-off layer (SOL) widths are analytically derived for L-mode diverted tokamak discharges by using a two-fluid model. The near SOL pressure and density decay lengths are obtained by leveraging a balance among the power source, perpendicular turbulent transport across the separatrix, and parallel losses at the vessel wall, while the far SOL pressure and density decay lengths are derived by using a model of intermittent transport mediated by filaments. The analytical estimates of the pressure decay length in the near SOL is then compared to the results of three-dimensional, flux-driven, global, two-fluid turbulence simulations of L-mode diverted tokamak plasmas, and validated against experimental measurements taken from an experimental multi-machine database of divertor heat flux profiles, showing in both cases a very good agreement. Analogously, the theoretical scaling law for the pressure decay length in the far SOL is compared to simulation results and to experimental measurements in TCV L-mode discharges, pointing out the need of a large multi-machine database for the far SOL decay lengths.
Permanent Link: http://hdl.handle.net/11104/0321143