[Back]

B. Labit, T. Eich, G. Harrer, E. Wolfrum, M. Bernert, M. Dunne, L. Frassinetti, P. Hennequin, R. Maurizio, A. Merle, H. Meyer, S. Saarelma, U. Sheikh, F. Laggner, TCV Team, . ASDEX Upgrade Team, EUROfusion MST1 Team et al.:
"Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade";
Nuclear Fusion, 59 (2019), 08602001 - 08602013.

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 (ne,sep/nG ∼ 0.3), 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.

H-mode, type-II ELMs, grassy ELMs, plasma triangularity, separatrix density, ballooning modes

http://dx.doi.org/10.1088/1741-4326/ab2211