Divertor Heat Flux Mitigation in High-Performance H-mode Plasmas in the National Spherical Torus Experiment [electronic resource].
- Published
- Washington, D.C. : United States. Dept. of Energy, 2008.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Physical Description
- PDF-file: 10 pages; size: 1.4 Mbytes
- Additional Creators
- Lawrence Berkeley National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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- Restrictions on Access
- Free-to-read Unrestricted online access
- Summary
- Experiments conducted in high-performance 1.0-1.2 MA 6 MW NBI-heated H-mode plasmas with a high flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high β{sub p} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the lower single null configuration with higher-end elongation 2.2-2.4 and triangularity 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m² to 0.5-2 MW/m² in ELMy H-mode discharges using high magnetic flux expansion and partial detachment of the outer strike point at several D₂ injection rates, while good core confinement and pedestal characteristics were maintained. The partially detached divertor regime was characterized by a 30-60% increase in divertor plasma radiation, a peak heat flux reduction by up to 70%, measured in a 10 cm radial zone, a five-fold increase in divertor neutral pressure, and a significant volume recombination rate increase.
- Report Numbers
- E 1.99:llnl-conf-407194
llnl-conf-407194 - Subject(s)
- Other Subject(s)
- Note
- Published through SciTech Connect.
09/22/2008.
"llnl-conf-407194"
Presented at: The 22nd IAEA Fusion Energy Conference, Geneva, Switzerland, Oct 13 - Oct 18, 2008.
Bell, R E; Gates, D; Roquemore, A L; Bush, C; Menard, J; Kaita, R; Maingi, R; Soukhanovskii, V A; Paul, S F; Raman, R. - Funding Information
- W-7405-ENG-48
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