Modular extension for systems codes for an improved calculation of the first-wall lifetime of DEMO

In the early design phase of a nuclear fusion demonstration power plant (DEMO), systems codes remain major tools for exploring the range of reasonable design parameters. Nevertheless present systems codes lack in estimating the lifetime of a reactor first-wall (FW). Hence an important criteria for feasibility assessment of a DEMO design is not yet included in system studies. For example charge exchange (CX) results in severe FW damage, if the magnetic configuration allows hot neutral particles to be formed in regions of hot plasma. Consequently these hot neutrals sputter a substantial amount of wall material, when impinging with energies above 1 keV. For these reasons a 1-dimensional (1d) Monte-Carlo (MC) code was developed for estimation of the lifetime of a DEMO full-tungsten (W) FW in the main chamber that calculated the sputtering of wall material by incident ions and secondary CX neutrals. Also, the code requested ion fluxes incident to the FW, and 1d radial profiles that were extended by an edge pedestal scaling, and described electron temperature and density. More important it determined the FW lifetime as a dependent property of the magnetic configuration. To sum up, the modular extension code was developed according to the specific demands of systems codes and was ultimately benchmarked with the well established 3d MC Code EIRENE.