[S-MP23] Physics and Chemistry of Minerals

[SMP23-P02] Velocity measurement of aqueous solution under high pressure and high-pressure ice by GHz-DAC velocity measurement method

*Ryosuke Matsui¹, Takuto Kato¹, Akira Yoneda¹, Tadashi Kondo¹ (1.Osaka University)

Keywords:ultra-high pressure, sound velocity measurement, subsurface ocean, high-pressure ice

We are developing and improving a method for measuring the speed of elastic waves in samples called the GHz-DAC sound velocity measurement method, which combines the GHz method, one of the ultrasonic measurement methods, and the diamond anvil cell (DAC), a high-pressure generating device. In this study, we aimed to develop a measurement technique that uses this method to measure the sound velocity under GPa conditions of water-salt aqueous solutions and their high-pressure solid phases. These are considered to be important basic information for future underground exploration plans for ice satellites. In addition, sound velocity measurements of liquids under pressure are limited in precedent, and the development of sound velocity methods for pressure liquid phases that can be measured in the laboratory is also highly important. In the presentation, we attempted to acquire signals using the GHz-DAC sound velocity measurement method near 1 GPa, targeting pure H2O liquid and high-pressure ice (phase Ⅵ) as samples for future aqueous solution samples, to optimize experimental conditions such as anvil material and gasket size. In this presentation, we report on the usefulness of the GHz-DAC sound velocity measurement method and the measurement results of actual water-ice samples.