Speaker
Description
Daigo Kanamori, Keisuke Mukai, Makoto. I. Kobayashi,
a The Graduate University for Advanced Studies, SOKENDAI, Toki, Gifu 509-5292,Japan
b National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
Keywords : Solid breeder materials, Li-depletion, thermal conductivity, molecular dynamics
To realize fusion reactor, it is necessary to develop tritium breeders and neutron multiplier materials. We focus on Li-Be oxides which can work as both breeder and multiplier. Especially, Li2BeSiO4 is possible to work as an accident tolerant material because of its extremely low reactivity with water vaper [1]. Also, Samolyuk [2] reported that Li2BeSiO4 have thermal conductivity about three times higher than that of the conventional candidates. Since the higher thermal conductivity is an advantage for a fusion reactor, Li2BeSiO4 can be the promising candidate for fusion blanket. However, it is foreseen that Li concentration would be decreased due to burn up under a reactor operation. The loss of Li introduces vacancies at Li sites, leading to reduction of thermal conductivity. It is necessary to evaluate the effect of Li-depletion on the thermal conductivity for the application of Li2BeSiO4.
In this study, we investigated the effect of Li-depletion on thermal conductivity of Li2BeSiO4 using experiments and molecular dynamics simulation. LiOH·H2O, BeO and SiO2 will be mixed and sintered in an atmosphere controllable furnace to synthesize Li2xBeSiO4 (x=1, 0.95, 0.9, and 0.8). The structure of these synthesized specimens will be analyzed by X-ray diffraction (XRD) to estimate the phase compositions such as Li2BeSiO4, BeO and Be2SiO4 . The thermal diffusivity are to be measured by laser-flush method. Furthermore, calculation results of thermal conductivity using Green-Kubo methods with universal machine learning potential will be reported at the workshop. The effect of Li-depletion on thermal conductivity will be discussed from these results.
