Power loads to misaligned edges in COMPASS

0451082 - ÚFP 2016 FR eng C - Conference Paper (international conference)
Dejarnac, Renaud - Corre, C. - Vondráček, Petr - Gardarein, J.-L. - Gauthier, E. - Gunn, J. P. - Horáček, Jan - Hron, Martin - Komm, Michael - Pánek, Radomír - Pitts, R. A.
Power loads to misaligned edges in COMPASS.
15th International Conference on PLASMA-FACING MATERIALS and COMPONENTS for FUSION APPLICATIONS. Aix-en-Provence: Commissariat à l'Energie Atomique, 2015.
[International Conference on PLASMA-FACING MATERIALS and COMPONENTS for FUSION APPLICATIONS/15./. Aix-en-Provence (FR), 18.05.2015-22.05.2015]
Institutional support: RVO:61389021
Keywords : Heat loads * limiter * leading edge * IR thermography
Subject RIV: BL - Plasma and Gas Discharge Physics
http://irfm.cea.fr/pfmc15/index.html

A major issue for ITER divertor are leading edges (LE) between monoblocks. Geometrical arguments assume that power loads on the top and side of a LE may be described by Qn = q//,0*sin(α) and Qs = q//,0*cos(α), respectively. This assumption has recently been challenged by edge melting experiments on JET, which found that the theoretically expected Qs needed to be reduced by a factor 5 (fs = 0.2) in L-mode to explain the observed power load, whilst Qn was as expected (fn = 1), violating power balance. A dedicated experiment has thus been designed on COMPASS to study this phenomenon. Simulations of this experiment show mitigation factors (0.5 < fs < 0.8) increasing with LE misalignment and find that missing power to the side is re-deposited on the next tile top surface, yielding fn > 1 consistent with power balance. Using simulated power load profiles input to 2D thermal calculations agree well with IR data. Importantly, low values of fs reported in JET case are not observed in COMPASS
Permanent Link: http://hdl.handle.net/11104/0252313