Drift mechanism of scrape-off layer formation in a tokamak

The tokamak scrape-off layer (SOL) model is discussed on the assumption of drift mechanisms of electron heat transport and dominant role of recycling outside the separatrix comparing to the ion outflow from the core. The SOL width estimate is given. It is shown that drift mechanisms give minimal SOL width corresponding to present day scalings which is close by the order of magnitude to the experimental values.