Physicochemical processes in blanket ceramic materials

Effect of external magnetic field (MF) on important physicochemical processes in ceramic blanket materials, the Li4SiO4 (FZK) and Li2TiO3 (CEA) ceramic pebbles, was studied. Stoichiometric amounts of the radiation-induced defects (RD) of the electron and hole type form at radiolysis of the ceramic materials. Colloid lithium forms only in Li4SiO4 under irradiation at the temperature 423–473 K and the dose 10–20 MGy. The magnetic field increases the radiolysis efficiency by 20–25% in both materials. The efficiency of formation of RD decreases with the increasing temperature of irradiation. Complete recombination of RD takes place at 873 K. The magnetic field retards the tritium release by lengthening the path of volume diffusion of charged tritium forms (T+). The substitution of 10 at.% of Ti4+ by Nb5+ produces additional cation vacancies in Li2TiO3 and increases the electrical conductivity by approximately 10 times at 1000 K. The constant of tritium diffusion is anticipated to be proportional to the electrical conductivity. The decrease of lithium content in Li2TiO3 ceramics simulating the lithium burn-up increases the electrical conductivity of ceramics.