13:45 〜 15:15
[SCG49-P06] 大容量プレスを用いた高圧下での高速時分割その場測定
キーワード：高圧、高速時分割、その場測定
The combination of synchrotron radiation and large-volume presses has been used to precisely determine the phase relation of Earth's mantle materials and to investigate the structure of the Earth's interior. In recent years, it becomes important to determine the rheological properties including crystallographic preferred orientation and viscosity in order to understand the dynamics of the Earth. Then, recent developments in in-situ measurement techniques using monochromatic X-rays from synchrotron radiation and deformation techniques of large-volume presses have made it possible to perform in situ stress-strain measurements up to the lower mantle pressure. Viscosity of bridgmanite at the lower mantle conditions was reported by Tsujino et al., (2022). On the other hand, the flux intensity of synchrotron radiation X-rays with bending magnet is relatively low. A series of stress-strain measurements (especially stress measurements) require 1 to 5 minutes. It is difficult to observe fast-moving dynamic processes such as fracture in sub-second time by in-situ measurements. Therefore, we performed in-situ radiographic images and 2-dimensional X-ray diffraction measurements in sub-second time at high temperature and pressure with undulator light source at BL05XU, SPring-8 and portable large-volume press.
Forsterite aggregate, which is the Mg-edge component of olivine, was used as a starting material. During in-situ measurements, temperature was oscillated by ~±250 dereeC in a 20-second cycle at ~1.5 GPa instead of stress oscillation. To enable fast slit size changes, rotary high-speed slit system was developed, allowing slit size switching at a maximum of 144 Hz. A camera system consisting of a GaGG scintillator and a CMOS camera was used for radiographic image measurements. A flat panel was used for 2-dimensional X-ray diffraction measurements. In this study, simultaneous in-situ measurements of the lattice volume change and sample length change with 6 Hz were conducted at BL05XU with temperature oscillation. Results shows that both lattice volume and sample length change simultaneously with temperature oscillation. This means that newly developed systems with undulator light source can measure fast moving dynamic process under high pressure conditions in sub-second time.
Forsterite aggregate, which is the Mg-edge component of olivine, was used as a starting material. During in-situ measurements, temperature was oscillated by ~±250 dereeC in a 20-second cycle at ~1.5 GPa instead of stress oscillation. To enable fast slit size changes, rotary high-speed slit system was developed, allowing slit size switching at a maximum of 144 Hz. A camera system consisting of a GaGG scintillator and a CMOS camera was used for radiographic image measurements. A flat panel was used for 2-dimensional X-ray diffraction measurements. In this study, simultaneous in-situ measurements of the lattice volume change and sample length change with 6 Hz were conducted at BL05XU with temperature oscillation. Results shows that both lattice volume and sample length change simultaneously with temperature oscillation. This means that newly developed systems with undulator light source can measure fast moving dynamic process under high pressure conditions in sub-second time.