Comparative studies of tungsten erosion and edge transport under partially detached divertor condition of CFETR with neon and argon seedings

Abstract

Neon (Ne) and argon (Ar) impurity seedings are recognized as effective techniques for reducing the divertor heat load in high-power operations of future reactors like CFETR. However, their influence on tungsten (W) erosion and edge transport remains unclear. Based on previously published SOLPS-ITER simulation results ([H. Si et al 2022 Nucl. Fusion 62 026031]), this study investigates the effects of Ne and Ar seedings on the W source and edge transport under partially detached divertor conditions on CFETR by DIVIMP simulations. The transport processes of Ne and Ar impurities in the boundary plasma are evaluated, with Ar expected to have better compression. Under similar partial detachment divertor conditions with the same total radiation power loss, the W leakage ability from divertor to the core plasma is demonstrated to be similar for Ne and Ar seeding cases. However, the W density in the core plasma is approximately four times lower in the Ar seeding case compared to the Ne seeding case, primarily due to the smaller W source from the divertor target. Therefore, the Ar seeding is proved to be more beneficial for reducing the W source and core W concentration than the Ne seeding.