Isotopic Tailoring to Improve the Breeding Capability of the Sn-Li Eutectic in Liquid First Wall Fusion Blanket Concepts

Due to its low vapor pressure, the Sn-Li eutectic has been identified as a potential breeder for deployment in the liquid first wall (FW)/Blanket concepts under investigation in the APEX study for high power density fusion reactors. However, its breeding capability is limited. This drawback is rather improved due to the neutron multiplication via Sn(n,2n) reactions. However, the "local" tritium breeding ratio (TBR) was found to be still on the marginal side (even with 90%Li-6 enrichment). Aside from using a beryllium multiplier, other means to improve the capability of Sn-Li for breeding are explored. In this paper, we show that by isotopic tailoring of Tin in the Sn-Li breeder, one can achieve substantial improvement in TBR in addition to attaining significant reduction in the activation level in this material.