Analysis of edge stability for models of heat flux width

Journal Article · Tue Aug 01 00:00:00 EDT 2017 · Nuclear Materials and Energy

DOI:https://doi.org/10.1016/j.nme.2017.04.008· OSTI ID:1356713

Makowski, M. A.; Lasnier, C. J.; Leonard, A. W.; Osborne, T. H.

Detailed measurements of the n_e, and T_e, and T_i profiles in the vicinity of the separatrix of ELMing H-mode discharges have been used to examine plasma stability at the extreme edge of the plasma and assess stability dependent models of the heat flux width. The results are strongly contrary to the critical gradient model, which posits that a ballooning instability determines a gradient scale length related to the heat flux width. The results of this analysis are not sensitive to the choice of location to evaluate stability. Significantly, it is also found that the results are completely consistent with the heuristic drift model for the heat flux width. Here the edge pressure gradient scales with plasma density and is proportional to the pressure gradient inferred from the equilibrium in accordance with the predictions of that theory.

• Research Organization: General Atomics, San Diego, CA (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE)
• Grant/Contract Number: AC52-07NA27344; FC02-04ER54698; AC02-09CH11466
• OSTI ID: 1356713
• Alternate ID(s): OSTI ID: 1374811
• Journal Information: Nuclear Materials and Energy, Journal Name: Nuclear Materials and Energy Vol. 12 Journal Issue: C; ISSN 2352-1791
• Publisher: Elsevier
• Country of Publication: Netherlands
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
36 MATERIALS SCIENCE