Assessment of the Impact of Magnetic Equilibria Designs on the Stationary Plasma Heat Flux Deposition onto the CFETR First Wall

Quasi-snowflake-plus (QSF+) and the lower single null diverted (SND) magnetic equilibria have been proposed as the promising designs for the Chinese fusion engineering testing reactor (CFETR). The impact of these two candidate magnetic equilibria on the H-mode stationary plasma heat flux deposition onto the first wall has been assessed. Comparing the distributions of plasma heat flux on the CFETR first wall for QSF + and SND indicates that the SND is more beneficial for the engineering design of the first wall module, since the computational results prove that there is only one module of the first wall being recognized as the enhanced heat flux module (EHFM) in the case of SND. Meanwhile, due to the SND magnetic equilibrium is the baseline configuration used in the CFETR design work and R_sep is an important factor for plasma control system (PCS) during the tokamak operation, the impact of SND magnetic equilibria with a series of R_sep on the plasma heat flux deposition onto the first wall is further studied. Comparing the peak plasma heat flux on the CFETR first wall for SND with varying R_sep builds more confidences in using R_sep = 6 cm as the baseline SND equilibrium in the CFETR design work, where the plasma heat flux on the first wall is close to current engineering constraints of 1 MW/m 2 . With the baseline SND equilibrium design, the sensitivity of plasma heat flux to power decay length will not be a priority for the safety of the first wall.