Simulation study of the radiative divertor with argon seeding for CFETR phase II.

Highlights • Heat exhaust issues are studied by SOLPS simulation for CFETR phase II with argon seeding. • Low core impurity density can be achieved for high electron density due to both the decrease in the required impurity concentration for fixed radiation power and the improvement of the impurity screening of divertor plasma. • The simulation results are fitted by the Matthew law, which can provide the relationship between the n e , Z eff , and P rad. Abstract For the future fusion reactor, where no intrinsic radiative impurity, like carbon, is allowed to exist, impurity seeding is an indispensable way to exhaust the power across the separatrix. Meanwhile, the impurity concentration has to be limited in order to avoid significant dilution of the fuel in core plasma. For CFETR phase II with a fusion power ∼1 GW, the radiative divertor with argon seeding is studied by SOLPS simulation. Under a high radiative power fraction ∼80% of the power across the separatrix, a density scan is performed for different deuterium ion density at the core-edge boundary. The divertor plasma is fully detached and impurity radiation is concentrated in the divertor region. The relationship between the electron density n e , effective charge Z eff and radiated power P rad are well fitted to the Matthew law, which is considered helpful to find a consistent operation scenario by further core-edge integrated modeling for CFETR phase II. [ABSTRACT FROM AUTHOR]