Measurements and 2-D Modeling of Recycling and Edge Transport in Discharges with Lithium-coated PFCs in NSTX

Conference · Sat Jan 01 04:00:00 EST 2011

OSTI ID:1036553

Canik, John ^[1]; Maingi, R. ^[2]; Soukhanovskii, V. A. ^[3]; Bell, R. E. ^[4]; Kugel, H. ^[4]; LeBlanc, B ^[4]; Osborne, T. H. ^[5]

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1. ORNL
2. Oak Ridge National Laboratory (ORNL)
3. Lawrence Livermore National Laboratory (LLNL)
4. Princeton Plasma Physics Laboratory (PPPL)
5. General Atomics, San Diego

The application of lithium coatings on plasma facing components has been shown to profoundly affect plasma performance in the National Spherical Torus Experiment, improving energy confinement and eliminating edge-localized modes. The edge particle balance during these ELM-free discharges has been studied through 2-D plasma-neutrals modeling, constrained by measurements of the upstream plasma density and temperature profiles and the divertor heat flux and D-alpha emission. The calculations indicate that the reduction in divertor D-alpha emission with lithium coatings applied is consistent with a drop in recycling coefficient from R similar to 0.98 to R similar to 0.9. The change in recycling is not sufficient to account for the change in edge density profiles: interpretive modeling indicates similar transport coefficients within the edge transport barrier (D/chi(e) similar to 0.2/1.0 m(2)/s), but a widening of the barrier with lithium. (C) 2010 Elsevier B.V. All rights reserved.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1036553
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COATINGS
CONFINEMENT
DIVERTORS
HEAT FLUX
LITHIUM
PERFORMANCE
PLASMA
PLASMA DENSITY
RECYCLING
SIMULATION
TRANSPORT