Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade

Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle the role of plasma fueling and plasma shape for the onset of small ELM regimes. On both devices, small ELM regimes with high confinement are achieved if and only if two condition...

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Bibliographic Details
Authors: Labit, Benoît; Eich, Thomas Hubert; Harrer, Georg Friedrich; Futatani, Shimpei|||0000-0001-5742-5454; Meyer, Han; Decker, Joan
Format: Article
Publication date:2019
Country:España
Institution:Universitat Politècnica de Catalunya (UPC)
Repository:UPCommons. Portal del coneixement obert de la UPC
Language:English
OAI Identifier:oai:upcommons.upc.edu:2117/364972
Online Access:https://hdl.handle.net/2117/364972
https://dx.doi.org/10.1088/1741-4326/ab2211
Access Level:Open access
Keyword:Nuclear physics
H-mode
Type-II ELMs
Grassy ELMs
Plasma triangularity
Separatrix density
Ballooning modes
Física nuclear
Àrees temàtiques de la UPC::Física
Description
Summary:Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle the role of plasma fueling and plasma shape for the onset of small ELM regimes. On both devices, small ELM regimes with high confinement are achieved if and only if two conditions are fulfilled at the same time. Firstly, the plasma density at the separatrix must be large enough (), leading to a pressure profile flattening at the separatrix, which stabilizes type-I ELMs. Secondly, the magnetic configuration has to be close to a double null (DN), leading to a reduction of the magnetic shear in the extreme vicinity of the separatrix. As a consequence, its stabilizing effect on ballooning modes is weakened.