Measurements of the high confinement mode pedestal region on Alcator C-Mod
- Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
Measurements of the steep transport barrier at the edge of the Alcator C-Mod tokamak [I. H. Hutchinson {ital et al.}, Phys. Plasmas {bold 1}, 1511 (1994)] are presented. The parameters at the top of this barrier are in the range T{sub e}=150{endash}750 eV and n{sub e}=0.5{minus}3.3{times}10{sup 20} m{sup {minus}3}, depending on the confinement regime. Type III edge localized modes (ELMs) have an upper temperature limit. T{sub e} pedestal profiles show a barrier width {Delta}{sub T}{approx_equal}8 mm. Soft x-ray emissivity profiles are narrower, with {Delta}=2{endash}4 mm. Edge currents are calculated to alter the ideal stability boundary favorably, leading to ideally stable pedestal profiles. High frequency, broadband, edge density fluctuations are sometimes observed in H-mode (high-confinement mode) and are associated with enhanced particle transport. Coherent magnetic fluctuations localized near the pedestal are also seen. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 610670
- Report Number(s):
- CONF-971103-; ISSN 1070-664X; TRN: 98:005372
- Journal Information:
- Physics of Plasmas, Vol. 5, Issue 5; Conference: 39. annual meeting of the Division of Plasma Physics of the American Physical Society, Pittsburgh, PA (United States), 17-21 Nov 1997; Other Information: PBD: May 1998
- Country of Publication:
- United States
- Language:
- English
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