THERMOCHEMICAL STUDY OF VAPORIZATION OF CERAMIC BREEDING MATERIALS BY KNUDSEN EFFUSION MASS-SPECTROMETRY

In order to evaluate the applicability of Li2SnO3 as a tritium breeding blanket material of a fusion reactor, a thermodynamic study of the vaporization of solid Li2SnO3 was performed by Knudsen effusion mass spectrometry. Partial vapor pressures of Li(g), O2(g), LiO(g), Li2O(g) and SnO(g) were determined over Li2SnO3. The measured partial pressure of Li(g) over Li2SnO3 is relatively high and ranks between those of Li2SiO3 and Li2TiO3. The Gibbs energy of formation of Li2SnO3 was obtained in the temperature range of 1455 to 1590 K. Computer calculations by use of the SOLGASMIX code proved that Li2SnO3 can show excellent performance as a breeder material with regard to tritium recovery and compatibility with stainless steel.