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

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 ne, effective charge Zeff and radiated power Prad 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.