Numerical study on CX-neutral transport and wall-sputtering in W7-AS diverted plasmas

Using the 3D SOL transport code EMC3/EIRENE, the paper presents a parameter study on CX-neutral transport and Fe-release from the wall due to physical sputtering in W7-AS diverted plasmas. The studies are restricted to the CX-neutrals induced by divertor and wall recycling processes. SOL plasma and divertor and wall recycling process are self-consistently calculated by the EMC3/EIRENE code. Island density is scanned across different confinement regimes. Cross-field transport coefficients are varied to cover an appropriate uncertainty range. Core plasma is prescribed, with the density profile, however, being switched between a peaked and a flat form typically measured for low and high density diverted plasmas. Studied are the sensitivities of the flux, energy spectrum and origin of the CX-neutrals to these parameters. In particular, it is aimed to identify under what condition and to what extent the edge islands can protect the wall from physical sputtering of the CX-neutrals.