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The shock physics of giant impacts: Key requirements for the equations of state

Stewart, Sarah and Davies, Erik and Duncan, Megan and Lock, Simon and Root, Seth and Townsend, Joshua and Kraus, Richard and Caracas, Razvan and Jacobsen, Stein (2020) The shock physics of giant impacts: Key requirements for the equations of state. In: Shock Compression of Condensed Matter - 2019. AIP Conference Proceedings. No.2272. American Institute of Physics , Melville, NY, Art. No. 080003. ISBN 978-0-7354-4000-5.

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We discuss major challenges in modeling giant impacts between planetary bodies, focusing on the equations of state (EOS). During the giant impact stage of planet formation, rocky planets are melted and partially vaporized. However, most EOS models fail to reproduce experimental constraints on the thermodynamic properties of the major minerals over the required phase space. Here, we present an updated version of the widely-used ANEOS model that includes a user-defined heat capacity limit in the thermal free energy term. Our revised model for forsterite (Mg₂SiO₄), a common proxy for the mantles of rocky planets, provides a better fit to material data over most of the phase space of giant impacts. We discuss the limitations of this model and the Tillotson equation of state, a commonly used alternative model.

Item Type:Book Section
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URLURL TypeDescription
Lock, Simon0000-0001-5365-9616
Kraus, Richard0000-0003-2752-0121
Additional Information:© 2020 Author(s). Published by AIP Publishing. Published Online: 04 November 2020. This work was supported by the Sandia Z Fundamental Science Program; DOE-NNSA DE-NA0002937 and DE-NA0003842; NASA NNX15AH54G; NASA NNX16AP35H; UC Office of the President LFR-17-449059. Sandia National Laboratories is a multimission laboratory managed and operated by NTESS, LLC, for the DOE-NNSA under contract DE-NA0003525. Prepared by LLNL under contract DE-AC52-07NA27344. Report No. SAND2019-8839J.
Funding AgencyGrant Number
Sandia Z Fundamental Science ProgramUNSPECIFIED
Department of Energy (DOE)DE-NA0002937
Department of Energy (DOE)DE-NA0003842
University of CaliforniaLFR-17-449059
Department of Energy (DOE)DE-NA0003525
Department of Energy (DOE)DE-AC52-07NA27344
Series Name:AIP Conference Proceedings
Issue or Number:2272
Record Number:CaltechAUTHORS:20201105-094348685
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106450
Deposited By: Tony Diaz
Deposited On:05 Nov 2020 18:28
Last Modified:02 Feb 2022 18:33

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