Plasma structures and transport in the SOL of the T-10 tokamak

Plasma regions (or structures) with high density are formed at or near the last closed flux surface (LCFS) in the T-10 tokamak. Plasma density inside the plasma structures is 1.5-2.5 times higher than the density of the background plasma. The structures move in radial direction and lead to an increase of the turbulent particle flux to the wall. The probability distribution function (PDF) of the turbulent particle flux is positively skewed in the scrape-off layer (SOL). The PDF is near Gaussian at the LCFS: the skewness is equal to zero, and the flatness is equal to 3. Negative particle flux bursts in this region correlate with lower-than-average density fluctuations, and are therefore interpreted as lower density plasma regions propagating towards the plasma core.