Modelling of Impurity Generation and Transport with a Monte Carlo Method based on Single Particle Motions

The generation and transport of impurity particles in a boundary plasma are analysed on the basis of a single particle motion together with a Monte Carlo method, where the Langevin-type equation of an impurity particle is used. The impurity generation and transport in a scrape-off layer are modelled after the Large Helical Device (LHD). The screening efficiency of the SOL for the impurity penetration into a core plasma, impurity redeposition on the first wall and the other effects are analysed from the statistics of traces of many impurites.