Geodynamics Research Center, Ehime University, Matsuyama, Japan.
J Synchrotron Radiat. 2009 Nov;16(Pt 6):757-61. doi: 10.1107/S0909049509034955. Epub 2009 Sep 15.
A system for stress measurement under high pressure has been developed at beamline BL04B1, SPring-8, Japan. A Kawai-type multi-anvil apparatus, SPEED-1500, was used to pressurize polycrystalline KCl to 9.9 GPa in a mechanically anisotropic cell assembly with the KCl sample sandwiched between dense Al(2)O(3) pistons. The variation of deviatoric stress was determined from the lattice distortion measured using two-dimensional X-ray diffraction with monochromatic synchrotron X-rays. The low-pressure B1 phase transformed to the high-pressure polymorph B2 during compression. The deviatoric stress increased with increasing pressure in both the B1 and B2 phases except for the two-phase-coexisting region at a pressure of 2-3 GPa. This new system provides one of the technical foundations for conducting precise rheological measurements at conditions of the Earth's lower mantle.
日本 SPring-8 光束线 BL04B1 开发了一种高压下的应力测量系统。采用 Kawai 式多砧装置 SPEED-1500，在具有机械各向异性的单元组件中，将多晶 KCl 加压至 9.9 GPa，KCl 样品夹在致密 Al(2)O(3)活塞之间。利用二维 X 射线衍射和同步加速器单色 X 射线测量晶格变形，确定偏应力的变化。在压缩过程中，低压 B1 相转变为高压多晶型 B2。除了在 2-3 GPa 的压力下两相共存的区域外，在 B1 和 B2 相中，偏应力随压力的增加而增加。该新系统为在地球下地幔条件下进行精确流变测量提供了技术基础之一。
