title: Statistical model for intermittent plasma edge turbulence.
abstract: The probability distribution function of plasma density fluctuations at the edge of fusion devices is known to be skewed and strongly non-Gaussian. The causes of this peculiar behavior are, up to now, largely unexplored. On the other hand, understanding the origin and the properties of edge turbulence is a key issue in magnetic fusion research. In this paper we show that a stochastic fragmentation model, already successfully applied to fluid turbulence, is able to predict an asymmetric distribution that closely matches experimental data. The asymmetry is found to be a direct consequence of intermittency. A discussion of our results in terms of recently suggested Bramwell-Holdsworth-Pinton universal curve [S. T. Bramwell, P. C. W. Holdsworth, and J.-F. Pinton, Nature (London) 396, 552 (1998)], that should hold for strongly correlated and critical systems, is also proposed.
authors.affiliation: Consorzio RFX, Corso Stati Uniti 4, 35127 Padova, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Sattin
authors.forename: N
authors.initials: N
authors.lastname: Vianello