Filters
Results 1 - 1 of 1
Results 1 - 1 of 1.
Search took: 0.025 seconds
Myra, J. R.; Zweben, S. J.; Russell, D. A.
Lodestar Research Corp., Boulder, CO (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States). Funding organisation: USDOE Office of Science - SC, Fusion Energy Sciences (FES) (SC-24) (United States)2018
Lodestar Research Corp., Boulder, CO (United States); Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States). Funding organisation: USDOE Office of Science - SC, Fusion Energy Sciences (FES) (SC-24) (United States)2018
AbstractAbstract
[en] We report that gas puff imaging (GPI) observations made in NSTX have revealed two-point spatial correlations of edge and scrape-off layer turbulence in the plane perpendicular to the magnetic field. A common feature is the occurrence of dipole-like patterns with significant regions of negative correlation. In this paper, we explore the possibility that these dipole patterns may be due to blob-hole pairs. Statistical methods are applied to determine the two-point spatial correlation that results from a model of blob-hole pair formation. It is shown that the model produces dipole correlation patterns that are qualitatively similar to the GPI data in several respects. Effects of the reference location (confined surfaces or scrape-off layer), a superimposed random background, hole velocity and lifetime, and background sheared flows are explored and discussed with respect to experimental observations. Additional analysis of the experimental GPI dataset is performed to further test this blob-hole correlation model. A time delay two-point spatial correlation study did not reveal inward propagation of the negative correlation structures that were postulated to correspond to holes in the data nor did it suggest that the negative correlation structures are due to neutral shadowing. However, tracking of the highest and lowest values (extrema) of the normalized GPI fluctuations shows strong evidence for mean inward propagation of minima and outward propagation of maxima, in qualitative agreement with theoretical expectations. Finally, other properties of the experimentally observed extrema are discussed.
Primary Subject
Source
DOE-ER--54678-12; DOE-ER--54392-89; LRC--18-174; OSTIID--1440543; FG02-02ER54678; FG02-97ER54392; AC02-09CH11466; Available from https://www.osti.gov/servlets/purl/1440543; DOE Accepted Manuscript full text, or the publishers Best Available Version will be available free of charge after the embargo period; arXiv:1805.06887; Country of input: United States
Record Type
Journal Article
Journal
Plasma Physics and Controlled Fusion; ISSN 0741-3335; ; v. 60(7); vp
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue