Heat loads on poloidal and toroidal edges of castellated plasma-facing components in COMPASS

0489810 - ÚFP 2019 RIV AT eng J - Journal Article
Dejarnac, Renaud - Corre, Y. - Vondráček, Petr - Gaspar, J. - Gauthier, E. - Gunn, J. P. - Komm, Michael - Gardarein, J.-L. - Horáček, Jan - Hron, Martin - Matějíček, Jiří - Pitts, R.A. - Pánek, Radomír
Heat loads on poloidal and toroidal edges of castellated plasma-facing components in COMPASS.
Nuclear Fusion. Roč. 58, č. 6 (2018), č. článku 066003. ISSN 0029-5515. E-ISSN 1741-4326
R&D Projects: GA ČR(CZ) GA16-14228S; GA MŠMT(CZ) LM2015045; GA MŠMT(CZ) 8D15001
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : heat loads * leading edge * gaps * PIC * castellated * PFC * IR * power deposition
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.516, year: 2018
http://iopscience.iop.org/article/10.1088/1741-4326/aab973/meta

Experiments have been performed in COMPASS to study power deposition processes on poloidal and toroidal edges of castellated PFCs. In the case of poloidal edges, when the contribution from local radiation is taken into account, q_par deduced from unperturbed, upstream measurements is fully consistent with the observed temperature increase at edges of various heights, respecting power balance assuming simple projection of the parallel flux density. The Larmor smoothing effect is found to be weak and the power deposition on poloidal edge is better described by the optical approximation, which is consistent with an electron-dominated regime (non-ambipolar conditions). In the case of toroidal gap, the different contributions of the total incoming flux along the gap have been observed experimentally for the first time. They confirm results of recent numerical studies performed for ITER showing that in specific cases the heat deposition does not necessarily follow the optical approximation.
Permanent Link: http://hdl.handle.net/11104/0284153