Dynamic Properties of Earth Materials

Ahrensburg-0207934该奖项将资助一系列的研究状态方程，声速，热化学性质，以及在系统MgO-SiO2中的重要模型地球材料的热导率，这些材料只能通过多孔，预热或特别合成的致密起始相的目标的冲击加载来获得。研究人员的多砧方法允许常规制备尺寸和形状适合高质量冲击压缩研究的地幔矿物多晶样品。实验与镁橄榄石，钛铁矿，wadsleyite，ringwoodite，和钙钛矿的起始材料和MgSiO 3玻璃和宝石质量顽火辉石的研究完成，将产生在多个内部能量状态的数据，从中提取下地幔条件下的Gruneisen参数。该奖项还将资助建造一个光学线成像VISAR（任何反射器的速度干涉仪系统），该系统将允许通过超越方法测量高冲击压力下的纵向和整体声速。这种方法可以比较矿物声速与地球本身，以及在超高压下的熔化温度的测定。多孔和预热MgO的实验将确定其熔化行为以上的范围内先前研究的金刚石细胞砧，解决理论的高压熔化模型MgO和目前的数据之间的巨大差异40 GPa。

AhrensEAR-0207934This award will fund a range of studies of the equations of state, sound velocity, thermochemical properties, and thermal conductivity of important model earth materials in the system MgO-SiO2 under conditions accessible only by shock loading of targets that are porous, pre-heated, or specially synthesized dense starting phases. The investigators' multianvil method allows routine preparation of polycrystalline samples of mantle minerals of a size and shape suitable for high-quality shock compression studies. Experiments with majorite, ilmentite, wadsleyite, ringwoodite, and perovskite starting materials and completion of studies on MgSiO3 glass and gem quality enstatite, will yield data at multiple internal energy states, from which the Gruneisen parameter will be extracted under lower mantle conditions. This award will also fund construction of an optical line-imaging VISAR (Velocity Interferometer System For Any Reflector) that will allow measurement of longitudinal and bulk sound velocities under high shock pressure by the overtaking method. This method allows comparison of mineral sound velocities with the Earth itself as well as determination of melting temperatures at ultra-high pressure. Experiments on both porous and preheated MgO will determine its melting behavior above the range previously studied with diamond cell anvils, resolving the enormous discrepancy between theoretical high pressure melting models for MgO and present data to 40 GPa.