Abstract
Soret effect was investigated by experiment on the ground (1g) and in microgravity (μg) aboard ISS-JEM. Temperature gradient was given to salol -tert-butyl alcohol solution, which was packed in a quartz cell. Interference fringes generated by two-wavelength Mach-Zehnder interferometer (wavelength: 532 and 780 nm) were recorded with using a CCD camera. The moving distance after setting temperature gradient was measured. The obtained interference fringes were straight and parallel, which indicates that there was not so significant convective disturbance. The curve of time dependence of the moving distance (number of crossing interference fringes) became smooth after correction considering the thermal expansion of the quartz cell. The obtained values of Soret coefficients were similar in two experiments with using vertical and parallel interference fringes.
