Ultrasound Resonance Measurements and Expansivity Measure- ments at 2000 K: Velocities of Sound at Mantle Temperatures

这项工作的目的是提高测量技术的能力，以达到最终目的：在下地幔温度范围内测量地幔矿物高压相弹性常数(和速度)的温度依赖性。这项工作的目的是1)将弹性常数测量的温度能力从1800K提高到2000K，2)将测量的样品尺寸缩小到亚毫米尺寸，3)在这种高温下测量含铁矿物，4)测量各种地幔矿物在1500K到2000K之间的热膨胀系数。所采用的方法是：1)利用新老技术对各种形状的小单晶进行共振超声；2)构造能够测量高温的激光干涉仪。这项工作的意义在于，它将使分离地球下地幔的矿物学具有更高的确定性，并将极大地增强热力学数据库，这将对地球化学和矿物学有用。

The objective of this work is to advance the capability of measurement techniques towards the ultimate objective which is to: Measure the temperature dependence of the elastic constants (and velocities) of high pressure phases of mantle minerals in the temperature range of the lower mantle. The objectives of this work are to 1) advance the temperature capability of elastic constant measurements from 1800 K to 2000 K, 2) to decrease the size of the sample measured to sub-millimeter size, 3) to measure iron-bearing minerals at these high temperatures, and 4) to measure the thermal expansivity between 1500 K and 2000 K on a variety of mantle minerals. The methods employed will be to 1) use old and new techniques of resonance ultrasound on small single crystals of various shapes, and 2) to construct a laser interferometer capable of high temperature dilametric measurement. The significance of this work, is that it will allow a higher certainty of isolating the mineralogy of the earth's lower mantle, and that it will greatly augment the thermodynamic database which will be useful for geochemistry and mineralogy.