Lithium lead titanate (Li2PbxTi1-xO3, 0.1<x<0.9): a new tritium-neutron complex breeder for fusion reactor blanket

Tritium breeder is an important functional material in d-T fusion reactor blanket serving the purpose of tritium re-production and energy conversion. Presently, Li ₂TiO ₃ ceramics is considered as the most promising solid tritium breeder for its good chemical stability, high mechanical strength and excellent tritium release performance. However, low lithium content and lithium evaporation at high temperature lead to a low tritium breeding ratio. In the paper the neutron multiplier element, Pb, is introduced into Li ₂TiO ₃ to obtain lithium lead titanate (Li ₂Pb _xTi _1-xO ₃) as tritium breeder, which combined the advantages of Pb and Li ₂TiO ₃ ceramic. Li ₂Pb _xTi _1-xO ₃ powders were synthesized via a sol-gel method, employing lithium acetate, tetrabutyl titanate, and lead acetate, with varying lead contents. The characterization results indicate that at a molar ratio of titanium to lead of 1:2, Li ₂TiO ₃-Li ₂PbO ₃ eutectic phase could be formed. The tritium breeding ratio (TBR) of Li ₂Pb _xTi _1-xO ₃ materials were evaluated by Monte Carlo Code, which was notably influenced by the lead content, exhibiting a continuous increase with higher Pb content and neutron energy. The Li ₂Pb _xTi _1-xO ₃ pebbles were prepared by freeze-drying route. The mechanical strength of Li ₂Pb _xTi _1-xO ₃ pebbles could be affected significantly by the lead content. Compared to the conventional Li ₂TiO ₃ ceramics, the Li ₂Pb _0.4Ti _0.6O ₃ ceramics exhibits a higher crushing load of 25.33 N.