TY - JOUR
T1 - Laser-driven shock compression of “synthetic planetary mixtures” of water, ethanol, and ammonia
AU - Guarguaglini, M.
AU - Hernandez, J. A.
AU - Okuchi, T.
AU - Barroso, P.
AU - Benuzzi-Mounaix, A.
AU - Bethkenhagen, M.
AU - Bolis, R.
AU - Brambrink, E.
AU - French, M.
AU - Fujimoto, Y.
AU - Kodama, R.
AU - Koenig, M.
AU - Lefevre, F.
AU - Miyanishi, K.
AU - Ozaki, N.
AU - Redmer, R.
AU - Sano, T.
AU - Umeda, Y.
AU - Vinci, T.
AU - Ravasio, A.
N1 - Funding Information:
The authors acknowledge the crucial contribution of the GEKKO XII and LULI2000 laser and support teams to the success of the experiments. The authors thank Marius Millot for his help in interpreting previous results on the synthetic Uranus. This research was supported by a French ANR grant to the POMPEI project (ANR-16-CE31-0008), the JSPS core-to-core program on International Alliance for Material Science in Extreme States with High Power Laser and XFEL, and the International Joint Research Promotion Program at the Osaka University. M.B., M.F. and R.R. acknowledge support from the Deutsche Forschungsgemeinschaft (DFG) within the FOR 2440 (Matter under Planetary Interior Conditions – High-Pressure, Planetary, and Plasma Physics). The DFT-MD simulations were performed at the North-German Supercomputing Alliance (HLRN) facilities and at the IT-and Media Center of the University of Rostock. This work has taken advantage of the MECMATPLA international collaboration.
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Water, methane, and ammonia are commonly considered to be the key components of the interiors of Uranus and Neptune. Modelling the planets’ internal structure, evolution, and dynamo heavily relies on the properties of the complex mixtures with uncertain exact composition in their deep interiors. Therefore, characterising icy mixtures with varying composition at planetary conditions of several hundred gigapascal and a few thousand Kelvin is crucial to improve our understanding of the ice giants. In this work, pure water, a water-ethanol mixture, and a water-ethanol-ammonia “synthetic planetary mixture” (SPM) have been compressed through laser-driven decaying shocks along their principal Hugoniot curves up to 270, 280, and 260 GPa, respectively. Measured temperatures spanned from 4000 to 25000 K, just above the coldest predicted adiabatic Uranus and Neptune profiles (3000–4000 K) but more similar to those predicted by more recent models including a thermal boundary layer (7000–14000 K). The experiments were performed at the GEKKO XII and LULI2000 laser facilities using standard optical diagnostics (Doppler velocimetry and optical pyrometry) to measure the thermodynamic state and the shock-front reflectivity at two different wavelengths. The results show that water and the mixtures undergo a similar compression path under single shock loading in agreement with Density Functional Theory Molecular Dynamics (DFT-MD) calculations using the Linear Mixing Approximation (LMA). On the contrary, their shock-front reflectivities behave differently by what concerns both the onset pressures and the saturation values, with possible impact on planetary dynamos.
AB - Water, methane, and ammonia are commonly considered to be the key components of the interiors of Uranus and Neptune. Modelling the planets’ internal structure, evolution, and dynamo heavily relies on the properties of the complex mixtures with uncertain exact composition in their deep interiors. Therefore, characterising icy mixtures with varying composition at planetary conditions of several hundred gigapascal and a few thousand Kelvin is crucial to improve our understanding of the ice giants. In this work, pure water, a water-ethanol mixture, and a water-ethanol-ammonia “synthetic planetary mixture” (SPM) have been compressed through laser-driven decaying shocks along their principal Hugoniot curves up to 270, 280, and 260 GPa, respectively. Measured temperatures spanned from 4000 to 25000 K, just above the coldest predicted adiabatic Uranus and Neptune profiles (3000–4000 K) but more similar to those predicted by more recent models including a thermal boundary layer (7000–14000 K). The experiments were performed at the GEKKO XII and LULI2000 laser facilities using standard optical diagnostics (Doppler velocimetry and optical pyrometry) to measure the thermodynamic state and the shock-front reflectivity at two different wavelengths. The results show that water and the mixtures undergo a similar compression path under single shock loading in agreement with Density Functional Theory Molecular Dynamics (DFT-MD) calculations using the Linear Mixing Approximation (LMA). On the contrary, their shock-front reflectivities behave differently by what concerns both the onset pressures and the saturation values, with possible impact on planetary dynamos.
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U2 - 10.1038/s41598-019-46561-6
DO - 10.1038/s41598-019-46561-6
M3 - Article
C2 - 31300690
AN - SCOPUS:85068968377
VL - 9
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 10155
ER -