Coupled IMPGYRO-EDDY simulation of tungsten impurity transport in tokamak geometry

We are developing a Monte Carlo transport code, ‘IMPGYRO’ for high-Z impurities. The code includes most of important process of high-Z impurities: (1) the finite Larmor radius effect in realistic tokamak geometries, (2) Coulomb collision of impurity ions with background ions and (3) multi-step ionization/recombination process. In this study, the IMPGYRO code is coupled to the EDDY code to improve the impurity generation model. The coupled code has been applied to the analysis of tungsten in a typical detachment state and has output the initial results. The code more precisely takes into account the effect of re-emission (reflection and self-sputtering). The resultant density inside the core becomes about two times larger than that with the previous simple impurity generation model. These initial results show that the coupling the IMPGYRO-EDDY code makes it possible to analyze not only the large-scale transport process of high-Z impurities in a realistic tokamak geometry, but also their re-emission process on the material surface more correctly.