Comparative assessment of application of low melting metals with capillary pore systems in a tokamak

Capillary-pore systems (CPS) with liquid metals are considered as advanced plasma facing material for application in DEMO-type fusion reactor. The estimation of opportunity of liquid Li, Ga and Sn application is carried out on the basis of its physical, chemical and technological properties, and with respect to prospective design of the tokamak in-vessel elements and technology. been shown that Li now is the most attractive and most investigated liquid metal for fusion devices application with CPS. The temperature limit for normal operation is about 550 °C and determined by appropriate Li flux to plasma due to evaporation. Wide range of structural materials is appropriate for Li based in-vessel elements. Sn are very corrosive and embrittlement inducing metals. As a result the temperature limit of these application is determined by compatibility with structural materials of CPS and in-vessel element. Only W can be used with Ga and Sn up to 500 °C. Moreover these metals have lower thermal properties comparing to Li. e temperature analysis for possible in-vessel element design (1 mm thick of porous W based CPS) has shown the similar power flux limit ∼21 MW/m2 for Li, Ga and Sn application at normal operation. Taking into account the latent heat of vaporization and screening effect with re-radiation the CPS with Li has a priority at ELM and disruption conditions.