High-Precision Equations of State Through Standardized Sample Synthesis

GSTDTAP

项目编号	1724693
	High-Precision Equations of State Through Standardized Sample Synthesis
	Wendy Panero
主持机构	Ohio State University
项目开始年	2017
	2017-07-01
项目结束日期	2020-06-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	267289(USD)
国家	美国
语种	英语
英文摘要	The composition, structure, and evolution of the Earth, planets in the Solar System and exoplanets, can only be examined in detail with precise models for the relationship between pressure, temperature, and density of planetary materials. This proposal will engineer microfabricated samples to create standardized samples that eliminate many of the complications that affect the precision and accuracy of such measurements. A key outcome of the work will be a "round robin" series of experiments at multiple laboratory facilities to assess the relative effects of sample quality, variations in experimental facility, and analysis method. As the proposed experimental approach will produce thousands of identical samples in each synthesis, the samples will be available to the broader experimental community for equation of state replication, phase diagram and diffusion studies, and measurement of electrical and thermal conductivity. This proposal will support the training for a PhD student and up to 3 undergraduate students. All data and conclusions will be published in the scientific literature and presented at academic conferences. The inference that the composition of the Earth's core is a mixture of iron, nickel and a small amount of lighter elements arises from the recognition that the Earth's core has a density lower than that expected for pure iron or iron-nickel alloys. However, inferring the abundance and identity of light elements is limited by the precision and accuracy of the thermoelastic properties of iron and iron-nickel alloys, as the impact of light elements is constrained through the discrepancy between the physical properties of iron-nickel alloys and that of the core. To assess the differences between thermoelastic properties under Earth's core conditions requires (1) accurate equations of state of the end member substances, and (2) a precise and accurate extrapolation of equations of state to core conditions. This proposal (1) will develop a strategy to assess the accuracy of equations of state at high pressures and temperatures by comparing the impact of different experimental approaches when measured to high precision, and (2) will quantify the uncertainty of extrapolated equations of state. These goals will be accomplished through the manufacture of custom and reproducible samples for use in the laser-heated diamond anvil cell focusing on the equations of state of hcp and fcc iron and iron-nickel alloys to high pressure and temperature. In the second stage of this proposal, measurements will be repeated at multiple synchrotron end station facilities that employ differing temperature measurement strategies.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71226
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Wendy Panero.High-Precision Equations of State Through Standardized Sample Synthesis.2017.