Predictive modeling of a lithium vapor box divertor in NSTX-U using SOLPS-ITER

• DOI: 10.1016/j.nme.2021.101004
• Publication Date: 2021-04-19T12:24:58Z
• Authors: E.D. Emdee; R.J. Goldston; J.D Lore; X. Zhang
• Keywords: Fusion power; Electron temperature

The unmitigated heat flux in attached operation of a fusion power plant is predicted to be destructive any solid divertor surface. Detachment, whereby the plasma pressure drops significantly before reaching target thus greatly reducing and sputtering, will necessary ensure adequate lifetime facing components (PFCs). lithium vapor box aims detach via evaporating condensing surfaces. By near or at plate it closer main chamber, density gradient can created. This ties energy losses poloidal distance between detachment point. radiation zone then prevented from X-point as ionization rate decreases when front moves away target. Here we present Scrape Off Layer Plasma Simulator (SOLPS) simulations using an NSTX-U equilibrium PFC geometry. parameters for core boundary conditions, gas puff intensity, particle transport coefficients are chosen match experimental values. Acceptable agreement with Scrape-Off (SOL) widths found, indicating reasonable choice coefficients. In predictive simulations, added evaporation Predictions peak fluxes upstream impurity concentration given variety rates. Target electron temperature able reduced recombination levels (below 1 eV) rates 1⋅1023 Li/s, detachment. Peak lower outer could by much factor six while maintaining fractions below 2%. prevention midplane shown due increase frictional forces acting on deuterium puff. Lithium also redeposited close evaporator which favorable initial tests future capillary porous systems.