B2/Eirene modeling of EAST divertor target power loading with enhanced wall carbon source and additional neon injection

A major concern for EAST and future high-powered steady-state machines such as ITER is the power handling capability of the divertor target plates. Detailed modeling using the B2/Eirene code is carried out to assess the target power loading of the EAST divertor with both single-null and double-null configurations. A remarkable output is that an enhanced wall carbon source from chemical sputtering may lead to strong radiation in the plasma boundary, significantly reducing heat fluxes to the target plates, with little contamination to the core plasma at sufficiently high densities due to strong divertor screening. As a means of further reducing the power fluxes to the target plates and actively controlling the inner/outer divertor asymmetry in power loading, localized neon gas puffing from the outer divertor is investigated using B2/Eirene. The effect of this highly radiating impurity on target power loading and the consequence for core contamination is also presented.