The DIII-D summary contribution to the final INTOR workshop
In SIII-D, good H-mode confinement has been obtained with up to 6 MW of neutral-beam injection (NBI). In this report we summarize the essential features of divertor operation for DIII-D H-mode plasma. Briefly, our measurements show that: Large edge density and temperarture gradients are obtained with scale lengths of a few cm at the midplane; In the steady state, approximately 10-20% of the input power is deposited on the divertor plates in a region that is peaked on the separatrix and extends radially over )approx equal) 2-4 cm at the outboard intercept. More power (2:1) reaches the outboard intercept than the inboard; Low electron temperature (less than or equal to20eV) and high density (n/sub e//sup div/ )approx equal) n/sub e//sup main/ greater than or equal to 3-10 )times)10/sup 19/ m/sup -3/ at the divertor plates indicate that DIII-D obtains a high-recycling divertor during H-mode. DEGAS neutral transport modeling is consistent with these results; The duration of good H-mode confinement is limited by Edge Localized Modes (ELMs) rather than increasing impurity radiation; The dominant impurities, C and Ni are concentrated in the edge plasma (ra greater than or equal to 0.5) for I/sub p/ greater than or equal to 1 MA; and Global impurity concentrations fall markedly with increasing plasma current. The remainder of this report contains a brief description of the DIII-D tokamak and the relavant diagnostics, a summary of the divertor plasma parameters obtained during the H-mode and the heat loads on the diverotr target plates. The results of measurements of the central radiation and impurity content using data from an EUV spectrometer and a 21 channel bolometer array are discussed, and finally a discussion of the implication of these results for the CIT and ITER tokamak designs is given. 8 refs., 8 figs
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); General Atomics Co., San Diego, CA (USA); Johns Hopkins Univ., Baltimore, MD (United States); Max-Planck-Institut fuer Plasmaphysik, Garching (Germany, F.R.); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States); Japan Atomic Energy Agency (JAEA), Tokai (Japan)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5181705
- Report Number(s):
- UCID-21329; ON: DE88008021
- Country of Publication:
- United States
- Language:
- English
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DOUBLET REACTORS
IMPURITIES
PLASMA CONFINEMENT
DIVERTORS
ELECTRON DENSITY
ELECTRON TEMPERATURE
HEAT FLUX
INTOR TOKAMAK
MAGNETIC FLUX
PLASMA DIAGNOSTICS
POWER DENSITY
TEMPERATURE GRADIENTS
CONFINEMENT
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
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