Japan Association of Mineralogical Sciences
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2023-06-01 |
| Journal | Elements |
| Authors |
Abstract
Section titled āAbstractāMost of the Earthās interior is a high-pressure, high-temperature environment, which makes high-pressure experimental techniques essential for studying Earth and planetary science.High-flux synchrotron radiation X-rays are important for in situ observations because the samples used in high-pressure experiments are generally very small (a few millimeters to a few microns), and X-ray absorption by the pressure medium and anvil is high.The SPring-8/BL04B1 beamline uses white X-rays emitted from bending magnets as a light source, enabling energy-dispersive X-ray diffraction measurements and X-ray radiography observations.The beamline also features a compact Si(111) double-crystal monochromator, which enables angle-dispersive X-ray diffraction measurements using monochromatic X-rays of 30-60 keV and monochromatic X-ray radiographic observations.The SPEED-1500 Kawai-type high-pressure apparatus (DIA-type block, optical hatch 2) and SPEED-Mk.II Kawaitype high-pressure apparatus (D-DIA-type mold, optical hatch 3) are installed, both with a maximum load of 1500 tons (Fig. 1).The SPEED-Mk.II can also be used for high-pressure and high-temperature experiments above 30 GPa using sintered diamond anvils and highpressure deformation experiments using the D-RAM (differential ram that can move independently of the main ram).For deformation experiments, it is necessary to obtain Debye rings all along the azimuth angle to measure deviatoric stresses.For this purpose, BL04B1 is normally equipped with a large-area CCD detector (Ļ200 mm, SX200, Rayonix), and a high-resolution X-ray beam monitor enables direct observation of minute sample deformations through X-ray absorption images.An example of a high-pressure experiment conducted at BL04B1 is the development of an elastic wave velocity measurement technique under very high pressure and temperature conditions.The lower mantle occupies about 60% of the Earthās total volume and is the primary arena