Structure, Stability and ELM Dynamics of the H-Mode Pedestal in DIII-D [electronic resource]
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Online Access (via OSTI) |
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Corporate Author: | |
Format: | Government Document Electronic eBook |
Language: | English |
Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Department of Energy ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2004.
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Subjects: |
Abstract: | Experiments are described that have increased understanding of the transport and stability physics that set the H-mode edge pedestal width and height, determine the onset of Type-I edge localized modes (ELMs), and produce the nonlinear dynamics of the ELM perturbation in the pedestal and scrape-off layer (SOL). Predictive models now exist for the n{sub e} pedestal profile and the p{sub e} height at the onset of Type-I ELMs, and progress has been made toward predictive models of the T{sub e} pedestal width and nonlinear ELM evolution. Similarity experiments between DIII-D and JET suggested that neutral penetration physics dominates in the relationship between the width and height of the n{sub e} pedestal while plasma physics dominates in setting the T{sub e} pedestal width. Measured pedestal conditions including edge current at ELM onset agree with intermediate-n peeling-ballooning (P-B) stability predictions. Midplane ELM dynamics data show the predicted (P-B) structure at ELM onset, large rapid variations of the SOL parameters, and fast radial propagation in later phases, similar to features in nonlinear ELM simulations. |
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Item Description: | Published through SciTech Connect. 10/13/2004. "ucrl-conf-207227" 45 12 ISSN 0029--5515. Presented at: 20th IAEA Fusion Energy Conference, Vilamoura (PT), 11/01/2004--11/06/2004. Fenstermacher, M E; Leonard, A W; Osborne, T H; Snyder, P B; Thomas, D M; Boedo, J A; Casper, T A; Colchin, R J; Groebner, R J; Groth, M; Kempenaars, M H; Loarte, A; Saibene, G; VanZeeland, M A; Zeng, L; Xu, X Q. |
Physical Description: | PDF-FILE: 14 ; SIZE: 2.2 MBYTES pages. |