Development of the Next Generation Megabar High-Pressure Cells: A COMPRES Grand Challenge

我们建议开发下一代静态超高压设备，它将允许在兆巴压力下将现有常规金刚石电池的样本量增加100倍以上。这将使目前无法用于超高压研究的无数主流分析技术成为可能，包括那些成功利用即将上线的主要中子和同步辐射设施所需的技术。新型高压电池还将提高现有原位探针技术的测量精度，提供校准良好的静水压力和均匀温度，允许激光加热达到更高和更均匀的温度，并提供稳健和用户友好的操作。这些能力需要解决当前高压地球化学、地球物理和行星科学中的许多问题；因此，预计拟议的进展将对上述每一个领域产生重大影响。新细胞的样本量的增加将来自于一系列改进的组合，包括扩大的砧、修改的凹槽形状、设计的垫圈和增加的砧的结合支持。在高压和高温下合成的单晶金刚石将通过同外延化学气相沉积使单晶金刚石薄膜过度生长而扩大，以产生达到25克拉以上的砧。合成莫桑石（SiC）砧将用于测试，并在高达50 GPa的压力下将体积增加100倍。更大的样品室将消除目前微观体积所施加的限制，并极大地改善压力-温度条件和超高压下的探测能力。新的印刷机将建成，以提供所需的负载为更大的体积。该项目将与新成立的地球科学材料特性研究联盟（COMPRES）协调开展，通过该联盟，新的高压能力将提供给高压地球科学社区

0135626HemleyWe propose to develop the next generation static ultrahigh-pressure apparatus that will allow an increase in sample volumes in excess of 100 times those currently available in conventional diamond cells at megabar pressures. This will enable myriad mainstream analytical techniques currently unavailable for ultrahigh-pressure research, including those required for the successful utilization of major neutron and synchrotron radiation facilities that are coming on line. The new class of high-pressure cells will also improve measurement accuracy for existing in situ probe techniques, provide well-calibrated hydrostatic pressures and uniform temperatures, allow higher and more uniform temperatures to be achieved with laser heating, and provide robust and user-friendly operation. These capabilities are required to address numerous current problems in high-pressure geochemistry, geophysics, and planetary science; as such, the proposed advances are expected to have major impact in each of these areas. The increases in sample volume for the new cells will result from a combination of improvements that include enlarged anvils, modified culet shapes, designed gaskets, and added binding support for the anvils. Single-crystal diamonds synthesized at high pressures and temperatures will be enlarged by homoepitaxial chemical vapor deposition overgrowth of single-crystal diamond films to create anvils reaching 25 carats and above. Synthetic moissanite (SiC) anvils will be used for testing and for 100-fold volume increases at pressures up to 50 GPa. The larger sample chamber, in turn, will remove restrictions currently imposed by microscopic volumes and greatly improve the pressure-temperature conditions and probing capabilities at ultrahigh pressures. New presses will be built to provide the loads necessary for the larger volumes. The project will be carried out in coordination with the newly formed COnsortium for Materials Properties Research in the Earth Sciences (COMPRES), through which the new high-pressure capabilities will be made available to the high-pressure geoscience community.***