Impurity Behavior in ITER and Helical Burning Plasmas with Internal Transport Barriers

The impurity transport simulation code TOTAL (TOroidal Transport Analysis Linkage) consisting of 1-D(dimensional) transport and 2or 3-D equilibrium is developed for analyzing tokamak and helical burning plasmas controlled by feedback scheme with gas puffing, pellet fueling injection and heating power modulations. In this code multi-species of impurity ions can be treated including neoclassical transport and adding radial electric field effects in helical plasmas. The permissible impurity concentrations for ITER operations are clarified first, and impurity radial profiles, especially carbon, iron and tungsten density profiles, are evaluated in tokamak and helical reactors. The effect of internal transport barrier (ITB) on impurity dynamics is also analyzed for ITER-like plasmas, and impurity shielding or concentrating mechanism induced by edge density modification is clarified.