Modeling of hydrogen isotopes release from lithium ceramics Li2TiO3 during in-situ experiments using vacuum extraction method

Abstract

Lithium ceramics Li2TiO3 in spherical granules (pebbles) is one of the most promising functional material for use in breeder blankets of a fusion reactor. In paper the experiments on a study of tritium and helium release from lithium ceramics Li2TiO3 (pebbles with a diameter of 1 mm, enrichment in 6Li is 96 %, weight ~ 0.37 g) under irradiation at the WWR-K research reactor (Almaty, Kazakhstan) are presented. The experiments showed that the main amount of tritium is released as HT molecules (the HT yield is an order of magnitude higher than T2 molecules yield). The release of tritium in the form of tritium water molecules was not recorded. The HT molecule yield's significant growth occurs at the initial moment with an increase in the ceramic temperature (while the T2 molecule release drops), after which the release flux decreases to the average level.The experimental results were evaluated by a qualitative model based on the obtained analytical expression for the tritium flux from a spherical ceramic sample for the given experimental conditions.