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Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas

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Show simple item record Mikkelsen, D. R. Bitter, M. Delgado-Aparicio, L. Hill, K. W. Candy, J. Waltz, R. E. Greenwald, Martin J Howard, Nathaniel Thomas Hughes Jr, Jerry Rice, John E Reinke, Matthew Logan Podpaly, Yuri A Ma, Y. 2017-09-13T20:12:57Z 2017-09-13T20:12:57Z 2015-06 2015-03
dc.identifier.issn 1070-664X
dc.identifier.issn 1089-7674
dc.description.abstract Peaked density profiles in low-collisionality AUG and JET H-mode plasmas are probably caused by a turbulently driven particle pinch, and Alcator C-Mod experiments confirmed that collisionality is a critical parameter. Density peaking in reactors could produce a number of important effects, some beneficial, such as enhanced fusion power and transport of fuel ions from the edge to the core, while others are undesirable, such as lower beta limits, reduced radiation from the plasma edge, and consequently higher divertor heat loads. Fundamental understanding of the pinch will enable planning to optimize these impacts. We show that density peaking is predicted by nonlinear gyrokinetic turbulence simulations based on measured profile data from low collisionality H-mode plasma in Alcator C-Mod. Multiple ion species are included to determine whether hydrogenic density peaking has an isotope dependence or is influenced by typical levels of low-Z impurities, and whether impurity density peaking depends on the species. We find that the deuterium density profile is slightly more peaked than that of hydrogen, and that experimentally relevant levels of boron have no appreciable effect on hydrogenic density peaking. The ratio of density at r/a = 0.44 to that at r/a = 0.74 is 1.2 for the majority D and minority H ions (and for electrons), and increases with impurity Z: 1.1 for helium, 1.15 for boron, 1.3 for neon, 1.4 for argon, and 1.5 for molybdenum. The ion temperature profile is varied to match better the predicted heat flux with the experimental transport analysis, but the resulting factor of two change in heat transport has only a weak effect on the predicted density peaking. en_US
dc.description.sponsorship United States. Department of Energy (Contract DE-AC02-09CH11466) en_US
dc.description.sponsorship United States. Department of Energy (Contract DE-FC02-99ER54512) en_US
dc.description.sponsorship United States. Department of Energy (Contract DE-FG02-95ER54309) en_US
dc.language.iso en_US
dc.publisher American Institute of Physics (AIP) en_US
dc.relation.isversionof en_US
dc.rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. en_US
dc.source MIT Plasma Science & Fusion Center en_US
dc.title Multispecies density peaking in gyrokinetic turbulence simulations of low collisionality Alcator C-Mod plasmas en_US
dc.type Article en_US
dc.identifier.citation Mikkelsen, D. R. et al. “Multispecies Density Peaking in Gyrokinetic Turbulence Simulations of Low Collisionality Alcator C-Mod Plasmas.” Physics of Plasmas 22, 6 (June 2015): 062301 © 2015 American Institute of Physics (AIP) en_US
dc.contributor.department Massachusetts Institute of Technology. Plasma Science and Fusion Center en_US
dc.contributor.department Massachusetts Institute of Technology. Department of Nuclear Science and Engineering en_US
dc.contributor.mitauthor Greenwald, Martin J
dc.contributor.mitauthor Howard, Nathaniel Thomas
dc.contributor.mitauthor Hughes Jr, Jerry
dc.contributor.mitauthor Rice, John E
dc.contributor.mitauthor Reinke, Matthew Logan
dc.contributor.mitauthor Podpaly, Yuri A
dc.contributor.mitauthor Ma, Y.
dc.relation.journal Physics of Plasmas en_US
dc.identifier.mitlicense PUBLISHER_POLICY en_US
dc.eprint.version Author's final manuscript en_US
dc.type.uri en_US
eprint.status en_US
dspace.orderedauthors Mikkelsen, D. R.; Bitter, M.; Delgado-Aparicio, L.; Hill, K. W.; Greenwald, M.; Howard, N. T.; Hughes, J. W.; Rice, J. E.; Reinke, M. L.; Podpaly, Y.; Ma, Y.; Candy, J.; Waltz, R. E. en_US
dspace.embargo.terms N en_US

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