Universal statistical properties of drift-interchange turbulence in TORPEX plasmas.
A unique parabolic relation is observed to link skewness and kurtosis of around ten thousand density fluctuation signals, measured over the whole cross section of a toroidal magnetized plasma for a broad range of experimental conditions. All the probability density functions of the measured signals, including those characterized by a negative skewness, are universally described by a special case of the Beta distribution. Fluctuations in the drift-interchange frequency range are necessary and sufficient to assure that probability density functions can be described by this specific Beta distribution.
Labit
B
B
Centre de Recherches en Physique des Plasmas (CRPP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Association EURATOM-Suisse CH-1015 Lausanne, Switzerland.
Furno
I
I
Fasoli
A
A
Diallo
A
A
Müller
S H
SH
Plyushchev
G
G
Podestà
M
M
Poli
F M
FM