Title :
Edge plasma analyses for KSTAR divertor design
Author :
Im, K.H. ; Han, J.H. ; Hill, D.N. ; Braams, B. ; Fenstermacher, M. ; Kim, J. ; Lee, B.J. ; Lee, G.S. ; Park, H.K.
Author_Institution :
Korea Basic Sci. Inst., Taejon, South Korea
Abstract :
The reduction of peak heat fluxes on KSTAR (Korea Superconducting Tokamak Advanced Research) divertor plates is required to meet the requirements of <3.5 MW/m2 heat flux and average and peak tile temperatures of <600°C and <1200°C, respectively, since numerical simulations give peak heat fluxes of 24.5 MW/m2 for the initial heating power of 15.5 MW with no impurity. The radiative divertor simulation obtained with neon concentration of 1.85% could collapse electron temperature and target plate heat flux well below the requirement. Zeff at core boundary was ~3. Study on geometry optimization shows that 7 cm of outboard pumping gap gives the best gas throughput and gas throughput can be improved by the proper selection of pumping shape. Core ionization could be reduced by a factor of 2 with inner bump structure. The effects of inboard pumping gap and cryopump are negligible compared to the outboard ones
Keywords :
Tokamak devices; fusion reactor design; plasma boundary layers; KSTAR divertor design; Korea Superconducting Tokamak Advanced Research; Ne concentration; core boundary; core ionization; cryopump; divertor plates; edge plasma analyses; electron temperature; gas throughput; geometry optimization; heat flux; inboard pumping gap; initial heating power; inner bump structure; neon concentration; outboard pumping gap; peak heat flux reduction; peak tile temperatures; pumping shape; radiative divertor simulation; target plate heat flux; Electrons; Geometry; Heating; Impurities; Numerical simulation; Plasma temperature; Shape; Throughput; Tiles; Tokamaks;
Conference_Titel :
Fusion Engineering, 1997. 17th IEEE/NPSS Symposium
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-4226-7
DOI :
10.1109/FUSION.1997.687736
