Current progress on fabrication processes of breeding functional materials for JA DEMO fusion applications

A JA DEMO blanket requires Be ₁₂V pebbles with 2 mm (or bigger) and Li ₂TiO ₃ with 0.2 mm as a mixed pebbles packing concept for achieving an 80 % packing fraction. The authors` group has achieved a significant milestone by successfully manufacturing Be ₁₂V pebbles through a pioneering rotating electrode process, marking a world-first achievement. Simultaneously, Li ₂TiO ₃ pebbles have been produced utilizing an emulsion process developed by the same research group. It is worth noting that most prior studies focused on pebbles with a 1 mm diameter, as this size was initially recommended for the ITER TBM before the introduction of the new packing concept. The rotating electrode process has successfully yielded Be ₁₂V pebbles measuring 2.5 mm or larger, and their characteristics have been thoroughly examined, offering a comprehensive overview of the current progress in Be ₁₂V pebble production. Furthermore, to meet the specific requirements of the JA DEMO blanket, experiments were conducted to fabricate smaller Li ₂TiO ₃ pebbles. It was discovered that Li ₂TiO ₃ pebbles with 0.3 mm could be successfully produced by adjusting the oil viscosity and flow ratio within the existing emulsion process system.