15 research outputs found
Experimental and numerical characterization of the turbulence in the scrape-off layer of MAST:Paper
Numerical simulations of interchange turbulence in the Scrape-Off Layer are
performed in a regime relevant for a specific L-mode MAST (Mega Ampere
Spherical Tokamak) discharge. Such a discharge was diagnosed with a
reciprocating arm equipped with a Gundestrup probe. A detailed comparison of
the average and statistical properties of the simulated and experimental ion
saturation current is performed. Good agreement is found in the time averaged
radial profile, in the probability distribution functions (PDFs) and in
qualitative features of the signals such as the shape, duration and separation
of burst events. These results confirm the validity of the simple interchange
model used and help to identify where it can be improved. Finally, the
simulated data are used to assess the importance of the temperature
fluctuations on plasma potential and radial velocity measurements acquired with
Langmuir probes. It is shown that the correlation between the actual plasma
quantities and the signal of the synthetic diagnostics is poor, suggesting that
accurate measurements of the temperature fluctuations are needed in order to
obtain reliable estimates of the perpendicular fluxes.Comment: 23 pages, 16 figures. This is an author-created, un-copyedited
version of an article accepted for publication in Plasma Physics and
Controlled Fusion. IOP Publishing Ltd is not responsible for any errors or
omissions in this version of the manuscript or any version derived from i