Temperature and Density on the Forsterite Liquid-Vapor Phase Boundary
| Autor: | D. K. Spaulding, Stein B. Jacobsen, Seth Root, E. J. Davies, M. S. Duncan, R. G. Kraus, Sarah T. Stewart |
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| Přispěvatelé: | Geosciences |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Physics
Phase boundary melting shock wave Liquid vapor Nuclear engineering Forsterite engineering.material Hugoniot Geophysics Space and Planetary Science Geochemistry and Petrology supercritical Earth and Planetary Sciences (miscellaneous) engineering Astrophysics::Earth and Planetary Astrophysics equation of state Research Article vaporization |
| Zdroj: | Journal of Geophysical Research. Planets |
| Popis: | The physical processes during planet formation span a large range of pressures and temperatures. Giant impacts, such as the one that formed the Moon, achieve peak pressures of 100s of GPa. The peak shock states generate sufficient entropy such that subsequent decompression to low pressures intersects the liquid‐vapor phase boundary. The entire shock‐and‐release thermodynamic path must be calculated accurately in order to predict the post‐impact structures of planetary bodies. Forsterite (Mg2SiO4) is a commonly used mineral to represent the mantles of differentiated bodies in hydrocode models of planetary collisions. Here, we performed shock experiments on the Sandia Z Machine to obtain the density and temperature of the liquid branch of the liquid‐vapor phase boundary of forsterite. This work is combined with previous work constraining pressure, density, temperature, and entropy of the forsterite principal Hugoniot. We find that the vapor curves in previous forsterite equation of state models used in giant impacts vary substantially from our experimental results, and we compare our results to a recently updated equation of state. We have also found that due to under‐predicted entropy production on the principal Hugoniot and elevated temperatures of the liquid vapor phase boundary of these past models, past impact studies may have underestimated vapor production. Furthermore, our results provide experimental support to the idea that giant impacts can transform much of the mantles of rocky planets into supercritical fluids. Key Points We performed reverse impact experiments and shock‐and‐release experiments to probe the density and temperature of the liquid‐vapor phase boundaryThe experimentally determined liquid‐vapor dome does not agree with commonly used equation of state modelsSupercritical post‐impact states are easier to achieve than previously modeled |
| Databáze: | OpenAIRE |
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