Please use this identifier to cite or link to this item:
http://arks.princeton.edu/ark:/88435/dsp01ft848t262
Title: | Two-dimensional turbulence cross-correlation functions in the edge of NSTX |
Contributors: | Zweben, S.J. Stotler, D.P. Scotti, F. Myra, J.R. U. S. Department of Energy contract number DE-AC02-09CH11466 |
Keywords: | Turbulence Tokamak NSTX Gas puff imaging |
Issue Date: | Sep-2017 |
Publisher: | Princeton Plasma Physics Laboratory, Princeton University |
Related Publication: | Physics of Plasmas (2017) |
Abstract: | The 2-D radial vs. poloidal cross-correlation functions of edge plasma turbulence were measured near the outer midplane using the gas puff imaging (GPI) diagnostic on NSTX. These correlation functions were evaluated at radii r= 0 cm, ±3 cm, and ±6 cm from the separatrix and poloidal locations p=0 cm and ±7.5 cm from the GPI poloidal center line for 20 different shots. The ellipticity ε and tilt angle φ of the positive cross- correlation regions, and the minimum negative cross-correlation “cmin” and total negative over positive values “neg/pos” were evaluated for each of these cases. The average results over this data set were ε=2.2±0.9, φ=87±34o (i.e. poloidally oriented), cmin= -0.30±0.15, and neg/pos=0.25±0.24. Thus there was significant variation in these correlation results within this database, with dependences on the location within the image, the magnetic geometry, and the plasma parameters. Possible causes for this variation are discussed, including the misalignment of the GPI view with the local B field line, the magnetic shear of field lines in the edge, the poloidal flow shear of the turbulence, blob-hole correlations, and the neutral density ‘shadowing’ effect in GPI. |
URI: | http://arks.princeton.edu/ark:/88435/dsp01ft848t262 |
Appears in Collections: | NSTX |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
ARK_DATA.zip | 191.3 kB | Unknown | View/Download | |
readme.txt | 4.37 kB | Text | View/Download |
Items in Dataspace are protected by copyright, with all rights reserved, unless otherwise indicated.