Numerical analyses of impurity behaviors for CFETR advanced scenarios by core-edge integrated simulations

The impurity behaviors for the advanced scenarios of CFETR with full tungsten divertor have been analyzed.Core plasma profiles for steady state and hybrid scenarios are simulated by consistently iterative transportcalculations within the OMFIT framework. The core-SOL integrated COREDIV code is then used to evaluate theeffects of different seeding impurities (Ne, Ar, Kr) with the OMFIT modelled core plasma parameters as input.The impurity behaviors for the two modelled scenarios are similar. Seeding by all the considered impurities caneffectively reduce the power to the divertor below the acceptable level. For Ne and Ar seeding, it is possible toachieve H-mode plasma operation with power from the core plasma to the SOL higher than L-H transition powerthreshold. However, higher Ne seeding rate would strongly reduce the fusion power due to the dilution effect. Krseeding seems to be infeasible because the power crossing the separatrix would be lower than the L-H transitionthreshold, when the seeding rate is high enough to meet the divertor requirements. Higher separatrix electrondensity or SOL diffusion can slightly reduce the core radiation. Although normal COREDIV simulations areperformed with a fixed H98 factor, simulations with fixed transport indicate that higher impurity seeding rateleads to a decrease of confinement and fusion gain, due to the increase of impurity radiation loss in the coreplasma.