Analysis of edge stability for models of heat flux width

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

doi:10.1016/j.nme.2017.04.008

Title: Analysis of edge stability for models of heat flux width

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Abstract

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.

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

Publication Date:: 2017-08-01

Research Org.:: General Atomics, San Diego, CA (United States)

Sponsoring Org.:: USDOE Office of Nuclear Energy (NE)

OSTI Identifier:: 1356713

Alternate Identifier(s):: OSTI ID: 1374811

Grant/Contract Number:: AC52-07NA27344; FC02-04ER54698; AC02-09CH11466

Resource Type:: Published Article

Journal Name:: Nuclear Materials and Energy

Additional Journal Information:: Journal Name: Nuclear Materials and Energy Journal Volume: 12 Journal Issue: C; Journal ID: ISSN 2352-1791

Publisher:: Elsevier

Country of Publication:: Netherlands

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 36 MATERIALS SCIENCE

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                    Makowski, M. A., Lasnier, C. J., Leonard, A. W., and Osborne, T. H. Analysis of edge stability for models of heat flux width.  Netherlands: N. p., 2017. 
Web.  doi:10.1016/j.nme.2017.04.008.

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                    Makowski, M. A., Lasnier, C. J., Leonard, A. W., & Osborne, T. H. Analysis of edge stability for models of heat flux width.  Netherlands.  https://doi.org/10.1016/j.nme.2017.04.008

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                    Makowski, M. A., Lasnier, C. J., Leonard, A. W., and Osborne, T. H. Tue .  
"Analysis of edge stability for models of heat flux width".  Netherlands.  https://doi.org/10.1016/j.nme.2017.04.008.

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@article{osti_1356713,

  title        = {Analysis of edge stability for models of heat flux width},

  author       = {Makowski, M. A. and Lasnier, C. J. and Leonard, A. W. and Osborne, T. H.},

  abstractNote = {Detailed measurements of the ne, and Te, and Ti 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.},

  doi          = {10.1016/j.nme.2017.04.008},

  journal      = {Nuclear Materials and Energy},

  number       = C,

  volume       = 12,

  place        = {Netherlands},

  year         = {2017},

  month        = {8}

}

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