Isotherms Reduced from Isentropes and Hugoniots up to Several 100 GPa
- Lyman Laboratory of Physics, Harvard University, Cambridge MA, 02138 (United States)
We have derived 300-K isotherms for static pressures as high as 300 GPa for Al, Cu, Ta and W. These isotherms are state-of-the-art equation-of-state (EOS) standards to calibrate the shift of the ruby fluorescence line as a function of pressure in diamond anvil cells (DACs). Recent measurements by Dewaele et al up to pressures of about 150 GPa in DACs motivated derivation of these isotherms. All experimental data used in this analysis were published previously. Hugoniot data are reduced to isotherms using thermal pressures calculated with mean field potential (MFP) theory and, for the first time, corrections were made using measured shock-induced strengths. Because this process has small systematic differences between different metal standards, it is important to obtain pressure by averaging results using many metals. Our purposes are (i) to give a brief description of how Hugoniots are reduced to isotherms and (ii) to articulate quasi-isentropes, Hugoniot data, and material strengths that need to be measured in the future for Al, Cu, Ta, W, Mo, Au, and Pt to improve the accuracies of the isotherms of these metals and to extend them to higher pressures. For calibration purposes, it is important that error bars be reported with such measurements.
- OSTI ID:
- 20875739
- Journal Information:
- AIP Conference Proceedings, Vol. 845, Issue 1; Conference: American Physical Society Topical Group conference on shock compression of condensed matter, Baltimore, MD (United States), 31 Jul - 5 Aug 2005; Other Information: DOI: 10.1063/1.2263262; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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