Comparative Study of the SN, DDN and DN Diverter Plasma Simulations for HCSB-DEMO

A comparative study of SN (single null), DDN (disconnected double-null) and DN (double null) diverters for HCSB-DEMO (helium-cooled solid breeder, HCSB) is reported in this paper by using the 2D edge plasma transport code SOLPS5.0. There is a heat power of 400 MW crossing CIB (core interface boundary). The peak heat flux at targets with different upstream densities is investigated. It is indicated that the peak heat flux at the outer target with a SN diverter is lower than that at the outer-down target with a DDN diverter under the same upstream density, but is higher than that at the outer target with a DN diverter. The diverter should operate at a proper upstream density to avoid strong high heat flux at the targets. The peak heat flux at the targets and first wall are sensitive to the SOL (scrape-off-layer) grid thickness. The simulated results will provide data for the design of diverter in HCSB-DEMO.