Effects of the flow of impurity particles across the magnetic field on their parameters in the tokamak scrape-off layer

The author proposes a simplified semi-analytical model describing the behaviour of impurity particles in the tokamak scrape-off layer which takes into account their flow along and across the magnetic field. The plasma parameters, density and temperature, are assumed to be constant across the magnetic field in the layer. It is shown that the movement of impurity atoms and ions across the magnetic surfaces should substantially alter their concentration distributions along the magnetic field lines. The impurity fluxes from the scrape-off layer into the tokamak working volume in the form of charged and neutral particles are determined. The dependence on the average energy of sputtered atoms and plasma density near the limiter is considered. (author)