Approaching detachment in I-mode Response of core confinement and the edge pedestal in the ASDEX Upgrade tokamak

0555702 - ÚFP 2022 RIV AT eng J - Journal Article
Happel, T. - Reinke, M.L. - Silvagni, D. - Bernert, M. - Grover, Ondřej - Hennequin, P. - Hubbard, A. E. - Plank, U. - Trier, E. - Brida, D. - David, P. - Fischer, R. - Gil, L. - Höfler, K. - Manz, P. - McDermott, R.M. - Merle, A. - Stroth, U. - Viezzer, E. - Willensdorfer, M.
Approaching detachment in I-mode Response of core confinement and the edge pedestal in the ASDEX Upgrade tokamak.
Nuclear Fusion. Roč. 61, č. 3 (2021), č. článku 036026. ISSN 0029-5515. E-ISSN 1741-4326
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : confinement regime * detachment * ELM-free * I-mode * nitrogen seeding * tokamak
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/abd7b7

Experiments on nitrogen assisted divertor detachment in the improved energy confinement mode (I-mode) are reported from the ASDEX Upgrade tokamak. When nitrogen is introduced into the divertor and radiation losses cool the divertor plasma down, a loss of core confinement is observed, concomitant with an increase in low frequency edge fluctuation levels. The loss in confinement can be compensated and the I-mode can be maintained by additional heating power input. Detachment of the inner divertor leg has been observed for the first time in an I-mode discharge. The outer divertor leg remains attached in these experiments. Good energy confinement properties (H 98(y, 2) = 0.9) during the detachment of the inner divertor leg are reported.
Permanent Link: http://hdl.handle.net/11104/0330166