TY - JOUR
T1 - Experimental and numerical characterization of the turbulence in the scrape-off layer of MAST
T2 - Paper
AU - Militello, F.
AU - Tamain, P.
AU - Fundamenski, W.
AU - Kirk, A.
AU - Naulin, Volker
AU - Nielsen, Anders Henry
PY - 2013
Y1 - 2013
N2 - Numerical simulations of interchange turbulence in the scrape-off layer are performed in a regime relevant for a specific L-mode Mega Ampere Spherical Tokamak (MAST) 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 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 us 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.
AB - Numerical simulations of interchange turbulence in the scrape-off layer are performed in a regime relevant for a specific L-mode Mega Ampere Spherical Tokamak (MAST) 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 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 us 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.
U2 - 10.1088/0741-3335/55/2/025005
DO - 10.1088/0741-3335/55/2/025005
M3 - Journal article
SN - 0741-3335
VL - 55
SP - 025005
JO - Plasma Physics and Controlled Fusion
JF - Plasma Physics and Controlled Fusion
IS - 2
ER -