Flow reversal, convection, and modeling in the DIII-D divertor
- University of California, San Diego, California 92093 (United States)
- Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
- General Atomics, P.O. Box 85608, San Diego, California 92186-9784 (United States)
- Sandia National Laboratory, Albuquerque, New Mexico 87185 (United States)
- Lawrence Livermore National Laboratory, Livermore, California 92093 (United States)
Measurements of the parallel Mach number of background plasma in the DIII-D tokamak divertor [M. A. Mahdavi {ital et al.} in {ital Proceedings, 16th International Conference}, Montreal, 1996 (International Atomic Energy Agency, Vienna, 1997) Vol. I, p. 397] were performed using a fast scanning Mach probe. The parallel particle flow shows evidence of complex behavior such as reverse flow, i.e., flow away from the target plate, stagnant flow, and large scale convection. For detached discharges, measurements confirm predictions of convective flow towards the divertor target plate at near sound speed over large regions in the divertor. The resulting convected heat flux is a dominant heat transport mechanism in the divertor. For attached discharges with high recycling, particle flow reversal in a thin region at or near the outer separatrix, thereby confirming the existence of a mechanism by which impurities can be transported away from the divertor target plates. Modeling results from the two-dimensional fluid code UEDGE [G. D. Porter and the DIII-D Team, {open_quotes}Divertor characterization experiments and modelling in DIII-D,{close_quotes} in {ital Proceedings of the 23rd European Conference on Controlled Fusion and Plasma Physics}, 24{endash}28 June 1996, Kiev, Ukraine (European Physical Society, Petit-Lancy, Switzerland, 1996), Vol. 20C, Part II, p. 699] can reproduce the main features of the experimental observations. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 664692
- Journal Information:
- Physics of Plasmas, Vol. 5, Issue 12; Other Information: PBD: Dec 1998
- Country of Publication:
- United States
- Language:
- English
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