Statistical analysis and modeling of intermittent transport events in the tokamak scrape-off layer

The turbulence observed in the scrape-off-layer of a tokamak is often characterized by intermittentevents of bursty nature, a feature which raises concerns about the prediction of heat loads on thephysical boundaries of the device. It appears thus necessary to delve into the statistical propertiesof turbulent physical fields such as density, electrostatic potential, and temperature, focusing on themathematical expression of tails of the probability distribution functions. The method followedhere is to generate statistical information from time-traces of the plasma density stemming fromBraginskii-type fluid simulations and check this against a first-principles theoretical model. The analysis of the numerical simulations indicates that the probability distribution function of the intermittent process contains strong exponential tails, as predicted by the analytical theory