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dc.contributor.authorKube, Ralph
dc.contributor.authorGarcia, Odd Erik
dc.contributor.authorTheodorsen, Audun
dc.contributor.authorBrunner, Daniel
dc.contributor.authorKuang, Adam
dc.contributor.authorLaBombard, Brian
dc.contributor.authorTerry, James L.
dc.date.accessioned2018-05-30T15:22:06Z
dc.date.available2018-05-30T15:22:06Z
dc.date.issued2018-04-10
dc.description.abstractThe Alcator C-Mod mirror Langmuir probe system has been used to sample data time series of fluctuating plasma parameters in the outboard mid-plane far scrape-off layer. We present a statistical analysis of one second long time series of electron density, temperature, radial electric drift velocity and the corresponding particle and electron heat fluxes. These are sampled during stationary plasma conditions in an ohmically heated, lower single null diverted discharge. The electron density and temperature are strongly correlated and feature fluctuation statistics similar to the ion saturation current. Both electron density and temperature time series are dominated by intermittent, large-amplitude burst with an exponential distribution of both burst amplitudes and waiting times between them. The characteristic time scale of the large-amplitude bursts is approximately 15 $\mu {\rm{s}}$. Large-amplitude velocity fluctuations feature a slightly faster characteristic time scale and appear at a faster rate than electron density and temperature fluctuations. Describing these time series as a superposition of uncorrelated exponential pulses, we find that probability distribution functions, power spectral densities as well as auto-correlation functions of the data time series agree well with predictions from the stochastic model. The electron particle and heat fluxes present large-amplitude fluctuations. For this low-density plasma, the radial electron heat flux is dominated by convection, that is, correlations of fluctuations in the electron density and radial velocity. Hot and dense blobs contribute only a minute fraction of the total fluctuation driven heat flux.en_US
dc.descriptionEmbargo of 12 months from date of publishing on accepted manuscript version. <br>Published version available in <a href=https://doi.org/10.1088/1361-6587/aab726>https://doi.org/10.1088/1361-6587/aab726> Plasma Physics and Controlled Fusion (2018) 60, (6), 065002</a><br>IOP publishing statement:<a href=http://ioppublishing.org/wp-content/uploads/2016/05/J-VAR-LF-0216-Author-Rights-New-5.pdf>http://ioppublishing.org/wp-content/uploads/2016/05/J-VAR-LF-0216-Author-Rights-New-5.pdf</a>en_US
dc.identifier.citationKube R, Garcia OE, Theodorsen A, Brunner D, Kuang A, LaBombard B, Terry JL. Intermittent electron density and temperature fluctuations and associated fluxes in the Alcator C-Mod scrape-off layer. Plasma Physics and Controlled Fusion. 2018;60(6)en_US
dc.identifier.cristinIDFRIDAID 1583126
dc.identifier.doi10.1088/1361-6587/aab726
dc.identifier.issn0741-3335
dc.identifier.issn1361-6587
dc.identifier.urihttps://hdl.handle.net/10037/12806
dc.language.isoengen_US
dc.relation.journalPlasma Physics and Controlled Fusion
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 electron density and temperature fluctuations and associated fluxes in the Alcator C-Mod scrape-off layeren_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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