Development of an ultrasonic acoustic interferometer for silicate liquids in an internally heated pressure vessel

EAR-0447113本项目的目标是开发一种高压声干涉仪，该干涉仪可用于测量内热压力容器(IHPV)中硅酸盐液体的声速和密度(以及可压缩性)。我们计划在高压下开发两种不同的技术：(1)测量液体声速的扫频法；(2)测量液体密度的反射系数法。我们将使用现有的IHPV，它可以在0.3 Gpa和1200摄氏度下运行。这笔赠款的资金将用于各种设备和机器车间的费用，并部分支持一名全职技术员。在地球科学中，测量高压下硅酸盐液体的密度和可压缩性是一项重要的实验任务，特别是在应用于含挥发分的熔体时。这些数据是准确计算晶体-熔体和深部流体-熔体平衡所必需的，而这些数据又是部分熔融、熔体迁移、结晶和脱气的定量模型以及岩浆喷发机制所必需的。参与该项目的研究生将获得热力学、声学和信号处理以及岩石学和地球化学方面的强大背景。预计我们开发的技术将在整个超声波和地球科学界得到广泛应用。

EAR-0447113Lange The goal of this project is the development of a high-pressure acoustic interferometer that can be used to measure the sound speed and density (and thus compressibility) of silicate liquids in an internally heated pressure vessel (IHPV). We plan to develop two different techniques at elevated pressure: (1) the frequency sweep method to measure liquid sound speed, and (2) the reflection coefficient method to measure liquid density. We will use an existing IHPV that is operable to 0.3 GPa and 1200 degrees celsius. Funds from this grant will be used for various equipment and machine shop costs and to partially support a full-time technician. Measurement of the density and compressibility of silicate liquids at high pressure is a major experimental imperative in the earth sciences, especially when applied to volatile-bearing melts. These data are needed for accurate thermodynamic calculations of crystal-melt and fluid-melt equilibrium at depth, which in turn are required for quantitative models of partial melting, melt transport, crystallization and degassing, and the mechanics of magma eruption. The graduate students involved in this project will obtain a strong background in thermodynamics, acoustics and signal processing, as well as petrology and geochemistry. It is anticipated that the techniques that we develop will become widely used throughout the ultrasonics and earth sciences community.