Hokkaido University Graduate School of Science
Hokkaido University Graduate School of Science
Hokkaido University Graduate School of Science
Ishikawajima Jet Service Co Ltd Space Department
Ishikawajima Jet Service Co Ltd Space Department
Ishikawajima-Harima Heavy Industries Co Ltd Space Experiment System Development Department
Ishikawajima-Harima Heavy Industries Co Ltd Space Experiment System Development Department
Ishikawajima-Harima Heavy Industries Co Ltd Space Experiment System Development Department
Ishikawajima-Harima Heavy Industries Co Ltd Space Experiment System Development Department
Ishikawajima-Harima Heavy Industries Co Ltd Space Experiment System Development Department
出版者
宇宙開発事業団
出版者(英)
National Space Development Agency of Japan (NASDA)
The microgravity experiment for measurement of self-diffusion of liquid lithium was carried out by means of TR-1A-6 rocket placing emphasis on the sample treatment and the construction of sample containers. The sample of lithium was prepared under a completely inert atmosphere to prevent the reaction with oxygen, nitrogen and water. The reactive lithium samples with different isotopic abundances were contained respectively in BN containers and BN container was placed in each stainless steel ampoule. The experiments using long capillary method were performed under microgravity at three different temperatures of 593, 643 and 673 K as well as the experiment for diffusion couple was done at 593 K with four independent furnaces in the multi-purpose furnace of TR-1A rocket. Throughout the course of the experiments, a slight pressure was applied to the liquid samples by means of tungsten spring to avoid the occurrence of Marangoni convection. The microgravity experiments were successfully performed with the temperature stability of +/-3 K and the holding time of 170 to 224 seconds. The diffusion coefficient was calculated from the concentration profiles. Investigation on diffusion coefficient of Li-6 in liquid Li-7 and Li-7 in liquid Li-6 revealed that lighter Li-6 diffuses faster than the heavier Li-7 with ratio of 1.3 at the largest. Theoretical analysis of self-diffusion of liquid lithium was carried out based on the hard sphere model of liquids with the packing fraction of 0.472. The calculations were found to give a fair agreement with experiment.