Analysis of a multi-machine database on divertor heat flux

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4710517· OSTI ID:1050410

Makowski, M A ^[1]; Elder, J D ^[2]; Gray, Travis K ^[3]; LaBombard, Brian ^[4]; Lasnier, C J ^[1]; Leonard, A W ^[5]; Maingi, Rajesh ^[3]; Osborne, T H ^[5]; Stangeby, P C ^[6]; Terry, J L ^[7]; Watkins, J G ^[8]

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1. Lawrence Livermore National Laboratory (LLNL)
2. University of Toronto, Toronto, ON, Canada
3. ORNL
4. Massachusetts Institute of Technology (MIT)
5. General Atomics
6. University of Toronto Institute for Aerospace Studies
7. MIT Plasma Science & Fusion Center, Cambridge, MA 02139 USA
8. Sandia National Laboratories (SNL)

A coordinated effort to measure divertor heat flux characteristics in fully attached, similarly shaped H-mode plasmas on C-Mod, DIII-D, and NSTX was carried out in 2010 in order to construct a predictive scaling relation applicable to next step devices including ITER, FNSF, and DEMO. Few published scaling laws are available and those that have been published were obtained under widely varying conditions and divertor geometries, leading to conflicting predictions for this critically important quantity. This study was designed to overcome these deficiencies. Analysis of the combined data set reveals that the primary dependence of the parallel heat flux width is robustly inverse with I-p, which all three tokamaks independently demonstrate. An improved Thomson scattering system on DIII-D has yielded very accurate scrape off layer (SOL) profile measurements from which tests of parallel transport models have been made. It is found that a flux-limited model agrees best with the data at all collisionalities, while a Spitzer resistivity model agrees at higher collisionality where it is more valid. The SOL profile measurements and divertor heat flux scaling are consistent with a heuristic drift based model as well as a critical gradient model.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1050410
• Journal Information: Physics of Plasmas, Vol. 19, Issue 5; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DIVERTORS
DOUBLET-3 DEVICE
HEAT FLUX
SCALING LAWS
SOLS
THOMSON SCATTERING
TRANSPORT