Turbulence in the near scrape-off layer towards the L-mode density limit inASDEX-Upgrade

0565122 - ÚFP 2023 RIV NL eng J - Journal Article
Grenfell, G. - Manz, P. - Conway, G.D. - Eich, T. - Adámek, Jiří - Brida, D. - Komm, Michael - Nishizawa, T. - Griener, M. - Tal, B. - Stroth, U.
Turbulence in the near scrape-off layer towards the L-mode density limit inASDEX-Upgrade.
Nuclear Materials and Energy. Roč. 33, October (2022), č. článku 101277. E-ISSN 2352-1791
EU Projects: European Commission(BE) 101052200
Institutional support: RVO:61389021
Keywords : Turbulence * Scrape-off layer * Electrostatic probes * Tokamaks * Density limit * Detachmen
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 2.6, year: 2022
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S2352179122001582?via%3Dihub

The L-mode density limit in ASDEX Upgrade is investigated with focus on the scrape-off layer. We observe a chain of events that involves the collapse of the E x B outer shear layer (just outside the separatrix), widening of the electron pressure fall-off length, outer divertor detachment, density shoulder formation, reduction and flattening of the parallel Mach number, and enhanced turbulent cross-field transport. The latter effect was associated with higher amplitude density fluctuations at low frequencies, where the turbulent cross-phase between density and velocity fluctuations pointing radially outward was favourable.
Permanent Link: https://hdl.handle.net/11104/0341370