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dc.contributor.authorGarcia, Odd Erik
dc.contributor.authorKube, Ralph
dc.contributor.authorTheodorsen, Audun
dc.contributor.authorLabombard, B
dc.contributor.authorTerry, J.L
dc.date.accessioned2019-03-05T09:23:33Z
dc.date.available2019-03-05T09:23:33Z
dc.date.issued2018-03-20
dc.description.abstractPlasma fluctuations in the scrape-off layer of the Alcator C-Mod tokamak in ohmic and high confinement modes have been analyzed using gas puff imaging data. In all cases investigated, the time series of emission from a single spatially resolved view into the gas puff are dominated by large-amplitude bursts, attributed to blob-like filament structures moving radially outwards and poloidally. There is a remarkable similarity of the fluctuation statistics in ohmic plasmas and in edge localized mode-free and enhanced D-alpha high confinement mode plasmas. Conditionally averaged waveforms have a two-sided exponential shape with comparable temporal scales and asymmetry, while the burst amplitudes and the waiting times between them are exponentially distributed. The probability density functions and the frequency power spectral densities are similar for all these confinement modes. These results provide strong evidence in support of a stochastic model describing the plasma fluctuations in the scrape-off layer as a super-position of uncorrelated exponential pulses. Predictions of this model are in excellent agreement with experimental measurements in both ohmic and high confinement mode plasmas. The stochastic model thus provides a valuable tool for predicting fluctuation-induced plasma–wall interactions in magnetically confined fusion plasmas.en_US
dc.description.sponsorshipU.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences: Award No. DE-FC02-99ER54512-CMOD.en_US
dc.descriptionThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Garcia, O. E., Kube, R., Theodorsen, A., Labombard, B. & Terry, J. (2018). Intermittent fluctuations in the Alcator C-Mod scrape-off layer for ohmic and high confinement mode plasmas. Physics of Plasmas, 25(5), and may be found at <a href=http://doi.org/10.1063/1.5018709> http://doi.org/10.1063/1.5018709</a>en_US
dc.identifier.citationGarcia, O. E., Kube, R., Theodorsen, A., Labombard, B. & Terry, J. (2018). Intermittent fluctuations in the Alcator C-Mod scrape-off layer for ohmic and high confinement mode plasmas. <i>Physics of Plasmas, 25</i>(5). http://doi.org/10.1063/1.5018709en_US
dc.identifier.cristinIDFRIDAID 1583049
dc.identifier.doi10.1063/1.5018709
dc.identifier.issn1070-664X
dc.identifier.issn1089-7674
dc.identifier.urihttps://hdl.handle.net/10037/14831
dc.language.isoengen_US
dc.publisherAIPen_US
dc.relation.journalPhysics of Plasmas
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/FRINATEK/240510/Norway/Turbulence and transport at the boundary of fusion plasmas//en_US
dc.rights.accessRightsopenAccessen_US
dc.subjectVDP::Mathematics and natural science: 400::Physics: 430::Space and plasma physics: 437en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Fysikk: 430::Rom- og plasmafysikk: 437en_US
dc.titleIntermittent fluctuations in the Alcator C-Mod scrape-off layer for ohmic and high confinement mode plasmasen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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