| Autor: |
D.N. Hill, S.L. Allen, N.H. Brooks, D. Content, J.C. DeBoo, P. Gohil, G. Haas, D. Heifetz, D. Hsieh, R.A. Hulse, G.L. Jackson, L. Lao, M.A. Mahdavil, M.J. Mayberry, N. Ohyabu, D.E. Perkins, M.E. Perry, T.W. Petrie, M.E. Rensink, T. Scoville, M. Shimada, R.T. Snider, R.E. Stockdale, R.D. Wood |
| Rok vydání: |
1988 |
| Předmět: |
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| Popis: |
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;more » 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« less |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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