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.
Centre de Recherches en Physique des Plasmas (CRPP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Association EURATOM-Suisse CH-1015 Lausanne, Switzerland.
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Fasoli
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Diallo
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Müller
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Plyushchev
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Podestà
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