Mineral physics studies using third-generation synchrotron facility

我们利用SPring-8的第三代同步辐射，利用多砧装置进行了矿物物理的各种研究，如高压相变的观测、相边界的测定、压力下熔融的探测和熔融温度的测定、高压相的P-V-T关系的测定等。在SPring-8高压地球科学光束线上进行了许多成功的实验，在压力高达25GPa，温度高达2000 ℃的条件下获得了丰富的结果。此外，已经尝试使用相对大尺寸（即，14mm边缘长度）的烧结金刚石砧来产生更高的压力。用这种方法在多砧装置上产生了40GPa的压力，并成功地观察到了Qa-MgSi_2O_6透辉石和MgAl_2O_4尖晶石的相变。此外，新的体积模量和热膨胀数据已 ...更多信息 我们与纽约州立大学斯托尼布鲁克分校的研究人员进行了一些合作。我们使用多砧装置合成了改性尖晶石型（Mg，Fe）2SiO4的热压样品，该装置被带到斯托尼布鲁克并用于高压下的超声测量。我们得到了一些信号的弹性波速度在这个标本的压力为13 GPa，目前正在分析。遗憾的是，由于同步辐射装置的射束时间有限，没有同时测量弹性速度和X射线衍射。尽管如此，我们同意在JSPS作为日美合作计划的财政支持下，继续在这一方向上进行两年的合作工作，该计划肯定会利用第三代同步辐射开发这一新技术。少

We made applications of the third-generation synchrotron radiation at SPring-8 to various studies in mineral physics, using multianvil apparatus, such as observations of high-pressure phase transitions, determination of phase boundaries, detection of melting and determination of melting temperature under pressure, determination of the P-V-T relations of high pressure phases. Many successful experiments were conducted in this direction at the High Pressure Earth Science beamline at SPring-8, and abundant results have been obtained at pressures up to 25 GPa, and at temperatures to 2000℃. Moreover, attempts have been made to use sintered diamond anvils of relatively large dimensions (i.e. 14 mm edge length) for higher pressure generation. Pressures to 40 GPa, are now produced in multianvil apparatus using this technique, and the observations of phase transitions in QaMgSi2O6 diopside and MgAI2O4 spinel has been successfully made. In addition, new bulk moduli and thermal expansion data hav … More e been obtained for the high pressure phases of these minerals, i.e. MgSi03 perovskite, CaSiO3 perovskite, and MgA12O4 calcium ferrite, which provide important constraints on the density of the mantle and of subducting slabs in the upper part of the lower mantle.We made some collaborations with the researchers in SUNY at Stony Brook. We synthesized a hot-pressed specimen of modified-spinel type (Mg,Fe)2SiO4 using a multianvil apparatus which was brought to Stony Brook and used for ultrasonic measurements under high pressure. We obtained some signals for elastic wave velocities in this specimen at pressures to 13 GPa, which are currently being analyzed. Unfortunately, the simultaneous measurements of the elastic velocities and X-ray diffraction were not conducted, because of the limited beamtime at the synchrotron radiation facility. Nevertheless, we agreed to continue collaborative work in this direction for another two years with the financial support from JSPS as Japan-US collaboration program, which will certainly develop this new technique using the third-generation synchrotron radiation. Less