Progress on Physical and Chemical Processes Deep Inside Ice Giants
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摘要: 宇宙中诸如天王星、海王星等冰巨行星的数量繁多,理解冰巨行星的内部结构与局部反应过程对于建立统一的行星演化体系具有重要意义。近几十年来,随着模拟计算方法、实验加载与诊断技术的不断发展,与冰巨行星内部相关的多个物理问题研究取得了突破性进展,如“超离子态水”、“钻石雨”等现象不再不可捉摸。聚焦冰巨行星相关物理问题,简要介绍并讨论了极端状态下的高压状态方程和微观物理过程的理论及实验研究进展,包括相关实验平台与配套技术的发展情况,并对该领域的未来发展方向提出了展望。Abstract: Ice giants such as Uranus and Neptune are numerous in the universe. Understanding the internal structure and local reaction processes of ice giants is of great significance for establishing a unified planetary evolution system. In recent decades, with the continuous development of simulation methods and experimental driving as well as diagnostic techniques, breakthroughs have been made in multiple physical problems related to the interior of ice giants, such as “superionic water” and “diamond rain”, which are no longer unpredictable. Starting from the physical issues related to ice giants, this article briefly introduces and discusses the theoretical and experimental research progress in high-pressure equations of state and microscopic physical processes under extreme conditions, as well as the development of related experimental platforms and supporting technologies. It also proposes prospects for the future direction of this field.
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Key words:
- ice giants /
- superionic water /
- diamond rain /
- dynamic in situ X-ray diagnosis
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图 2 不同混合物的BACF:(a) 不同温度下4种键的BACF,(b) 4000 K下的分子动力学模拟快照,(c) 不同混合物在4000 K、176 GPa下的BACF[13]
Figure 2. BACF of different mixtures: (a) BACF of four types of bond at different temperatures; (b) a snapshot of the molecular dynamics simulation at 4000 K; (c) BACF of different mixtures at 4000 K and 176 GPa[13]
图 6 (a)激光脉冲诱导液氨样品激波压缩实验装置示意图,(b) VISAR信号和 (c) SOP数据以及提取的速度和温度测量值,(d) 纯液态NH3样品的拉曼光谱,(e) NH3沿Hugoniot(黑色方块)的直流电导率[35]
Figure 6. (a) Schematic experimental setup of the laser pulse inducing shock compression in the liquid ammonia sample; (b) VISAR signal and (c) SOP data together with the extracted velocity and temperature measurements; (d) Raman spectrum of the sample indicative of pure liquid NH3; (e) calculated DC electrical conductivity of NH3 along the Hugoniot (black square)[35]
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[1] BORUCKI W J. Kepler mission: development and overview [J]. Reports on Progress in Physics, 2016, 79(3): 036901. doi: 10.1088/0034-4885/79/3/036901 [2] ROSS M. The ice layer in Uranus and Neptune: diamonds in the sky? [J]. Nature, 1981, 292(5822): 435–436. doi: 10.1038/292435a0 [3] NELLIS W J, HOLMES N C, MITCHELL A C, et al. Equation of state and electrical conductivity of “synthetic Uranus”, a mixture of water, ammonia, and isopropanol, at shock pressure up to 200 GPa (2 Mbar) [J]. The Journal of Chemical Physics, 1997, 107(21): 9096–9100. [4] STANLEY S, BLOXHAM J. Numerical dynamo models of Uranus’ and Neptune’s magnetic fields [J]. Icarus, 2006, 184(2): 556–572. doi: 10.1016/j.icarus.2006.05.005 [5] REDMER R, MATTSSON T R, NETTELMANN N, et al. The phase diagram of water and the magnetic fields of Uranus and Neptune [J]. Icarus, 2011, 211(1): 798–803. doi: 10.1016/j.icarus.2010.08.008 [6] NETTELMANN N, WANG K, FORTNEY J J, et al. Uranus evolution models with simple thermal boundary layers [J]. Icarus, 2016, 275: 107–116. doi: 10.1016/j.icarus.2016.04.008 [7] BETHKENHAGEN M, MEYER E R, HAMEL S, et al. Planetary ices and the linear mixing approximation [J]. The Astrophysical Journal, 2017, 848(1): 67. doi: 10.3847/1538-4357/aa8b14 [8] MILLOT M, COPPARI F, RYGG J R, et al. Nanosecond X-ray diffraction of shock-compressed superionic water ice [J]. Nature, 2019, 569(7755): 251–255. doi: 10.1038/s41586-019-1114-6 [9] KRAUS D, RAVASIO A, GAUTHIER M, et al. Nanosecond formation of diamond and lonsdaleite by shock compression of graphite [J]. Nature Communications, 2016, 7(1): 10970. doi: 10.1038/ncomms10970 [10] KRAUS D, VORBERGER J, PAK A, et al. Formation of diamonds in laser-compressed hydrocarbons at planetary interior conditions [J]. Nature Astronomy, 2017, 1(9): 606–611. doi: 10.1038/s41550-017-0219-9 [11] KRAUS D, HARTLEY N J, FRYDRYCH S, et al. High-pressure chemistry of hydrocarbons relevant to planetary interiors and inertial confinement fusion [J]. Physics of Plasmas, 2018, 25(5): 056313. doi: 10.1063/1.5017908 [12] STANLEY S, BLOXHAM J. Convective-region geometry as the cause of Uranus’ and Neptune’s unusual magnetic fields [J]. Nature, 2004, 428(6979): 151–153. doi: 10.1038/nature02376 [13] CHAU R, HAMEL S, NELLIS W J. Chemical processes in the deep interior of Uranus [J]. Nature Communications, 2011, 2(1): 203. doi: 10.1038/ncomms1198 [14] CHEN B, ZENG Q Y, YU X X, et al. Three-step formation of diamonds in shock-compressed hydrocarbons: decomposition, species separation, and nucleation [EB/OL]. (2022-08-03)[2023-08-18]. https://arxiv.org/abs/2208.01830v1. [15] LIU C, GAO H, WANG Y, et al. Multiple superionic states in helium-water compounds [J]. Nature Physics, 2019, 15(10): 1065–1070. doi: 10.1038/s41567-019-0568-7 [16] GAO H, LIU C, HERMANN A, et al. Coexistence of plastic and partially diffusive phases in a helium-methane compound [J]. National Science Review, 2020, 7(10): 1540–1547. doi: 10.1093/nsr/nwaa064 [17] LIU C, GAO H, HERMANN A, et al. Plastic and superionic helium ammonia compounds under high pressure and high temperature [J]. Physical Review X, 2020, 10(2): 021007. doi: 10.1103/PhysRevX.10.021007 [18] LIU C, SHI J Y, GAO H, et al. Mixed coordination silica at megabar pressure [J]. Physical Review Letters, 2021, 126(3): 035701. doi: 10.1103/PhysRevLett.126.035701 [19] GAO H, LIU C, SHI J Y, et al. Superionic silica-water and silica-hydrogen compounds in the deep interiors of Uranus and Neptune [J]. Physical Review Letters, 2022, 128(3): 035702. doi: 10.1103/PhysRevLett.128.035702 [20] HUANG T H, LIU C, WANG J J, et al. Metallic aluminum suboxides with ultrahigh electrical conductivity at high pressure [J]. Research, 2022, 2022: 9798758. doi: 10.34133/2022/9798758 [21] PAN S N, HUANG T H, VAZAN A, et al. Magnesium oxide-water compounds at megabar pressure and implications on planetary interiors [J]. Nature Communications, 2023, 14(1): 1165. doi: 10.1038/s41467-023-36802-8 [22] SHI J M, CUI W W, HAO J, et al. Formation of ammonia-helium compounds at high pressure [J]. Nature Communications, 2020, 11(1): 3164. doi: 10.1038/s41467-020-16835-z [23] ZHANG P, SHI J M, CUI W W, et al. Formation of NH3-Xe compound at the extreme condition of planetary interiors [J]. Physical Review B, 2022, 105(21): 214109. doi: 10.1103/PhysRevB.105.214109 [24] ZHANG J R, LV J, LI H F, et al. Rare helium-bearing compound FeO2 He stabilized at deep-earth conditions [J]. Physical Review Letters, 2018, 121(25): 255703. doi: 10.1103/PhysRevLett.121.255703 [25] BENEDETTI L R, NGUYEN J H, CALDWELL W A, et al. Dissociation of CH4 at high pressures and temperatures: diamond formation in giant planet interiors? [J]. Science, 1999, 286(5437): 100–102. doi: 10.1126/science.286.5437.100 [26] HIRAI H, KONAGAI K, KAWAMURA T, et al. Polymerization and diamond formation from melting methane and their implications in ice layer of giant planets [J]. Physics of the Earth and Planetary Interiors, 2009, 174(1): 242–246. doi: 10.1016/j.pepi.2008.06.011 [27] ZERR A, SERGHIOU G, BOEHLER R, et al. Decomposition of alkanes at high pressures and temperatures [J]. High Pressure Research, 2006, 26(1): 23–32. doi: 10.1080/08957950600608931 [28] ANCILOTTO F, CHIAROTTI G L, SCANDOLO S, et al. Dissociation of methane into hydrocarbons at extreme (planetary) pressure and temperature [J]. Science, 1997, 275(5304): 1288–1290. doi: 10.1126/science.275.5304.1288 [29] GAO G Y, OGANOV A R, MA Y M, et al. Dissociation of methane under high pressure [J]. The Journal of Chemical Physics, 2010, 133(14): 144508. doi: 10.1063/1.3488102 [30] LOBANOV S S, CHEN P N, CHEN X J, et al. Carbon precipitation from heavy hydrocarbon fluid in deep planetary interiors [J]. Nature Communications, 2013, 4(1): 2446. doi: 10.1038/ncomms3868 [31] NETTELMANN N, HELLED R, FORTNEY J J, et al. New indication for a dichotomy in the interior structure of Uranus and Neptune from the application of modified shape and rotation data [J]. Planetary and Space Science, 2013, 77: 143–151. doi: 10.1016/j.pss.2012.06.019 [32] LEE M S, SCANDOLO S. Mixtures of planetary ices at extreme conditions [J]. Nature Communications, 2011, 2(1): 185. doi: 10.1038/ncomms1184 [33] KADOBAYASHI H, OHNISHI S, OHFUJI H, et al. Diamond formation from methane hydrate under the internal conditions of giant icy planets [J]. Scientific Reports, 2021, 11(1): 8165. doi: 10.1038/s41598-021-87638-5 [34] NELLIS W J, HAMILTON D C, MITCHELL A C. Electrical conductivities of methane, benzene, and polybutene shock compressed to 60 GPa (600 kbar) [J]. The Journal of Chemical Physics, 2001, 115(2): 1015–1019. doi: 10.1063/1.1379537 [35] RAVASIO A, BETHKENHAGEN M, HERNANDEZ J A, et al. Metallization of shock-compressed liquid ammonia [J].Physical Review Letters, 2021, 126(2): 025003. doi: 10.1103/PhysRevLett.126.025003 [36] CELLIERS P M, BRADLEY D K, COLLINS G W, et al. Line-imaging velocimeter for shock diagnostics at the Omega laser facility [J]. Review of Scientific Instruments, 2004, 75(11): 4916–4929. doi: 10.1063/1.1807008 [37] MILLER J E, BOEHLY T R, MELCHIOR A, et al. Streaked optical pyrometer system for laser-driven shock-wave experiments on Omega [J]. Review of Scientific Instruments, 2007, 78(3): 034903. doi: 10.1063/1.2712189 [38] BARRIOS M A, HICKS D G, BOEHLY T R, et al. High-precision measurements of the equation of state of hydrocarbons at 1–10 Mbar using laser-driven shock waves [J]. Physics of Plasmas, 2010, 17(5): 056307. doi: 10.1063/1.3358144 [39] BARRIOS M A, BOEHLY T R, HICKS D G, et al. Precision equation-of-state measurements on National Ignition Facility ablator materials from 1 to 12 Mbar using laser-driven shock waves [J]. Journal of Applied Physics, 2012, 111(9): 093515. doi: 10.1063/1.4712050 [40] LÜTGERT J, VORBERGER J, HARTLEY N J, et al. Measuring the structure and equation of state of polyethylene terephthalate at megabar pressures [J]. Scientific Reports, 2021, 11(1): 12883. doi: 10.1038/S41598-021-91769-0 [41] GORMAN M G, BRIGGS R, MCBRIDE E E, et al. Direct observation of melting in shock-compressed bismuth with femtosecond X-ray diffraction [J]. Physical Review Letters, 2015, 115(9): 095701. doi: 10.1103/PhysRevLett.115.095701 [42] HE Z Y, RÖDEL M, LÜTGERT J, et al. Diamond formation kinetics in shock-compressed C-H-O samples recorded by small-angle X-ray scattering and X-ray diffraction [J]. Science Advances, 2022, 8(35): eabo0617. doi: 10.1126/sciadv.abo0617 [43] 李俊, 陈小辉, 吴强, 等. 基于原位X射线衍射技术的动态晶格响应测量方法研究 [J]. 物理学报, 2017, 66(10): 136101. doi: 10.7498/aps.66.136101LI J, CHEN X H, WU Q, et al. Experimental investigation on dynamic lattice response by in-situ Xray diffraction method [J]. Acta Physica Sinica, 2017, 66(10): 136101. doi: 10.7498/aps.66.136101 [44] KRAUS R G, HEMLEY R J, ALI S J, et al. Measuring the melting curve of iron at super-Earth core conditions [J].Science, 2022, 375(6577): 202–205. doi: 10.1126/science.abm1472 [45] 陈小辉, 谭伯仲, 薛桃, 等. 高压高应变率加载下多晶相变的原位X射线衍射 [J]. 物理学报, 2020, 69(24): 246201. doi: 10.7498/aps.69.20200929CHEN X H, TAN B Z, XUE T, et al. In situ observation of phase transition in polycrystalline under high-pressure high-strain-rate shock compression by X-ray diffraction [J]. Acta Physica Sinica, 2020, 69(24): 246201. doi: 10.7498/aps.69.20200929 [46] DUNAEVA A N, ANTSYSHKIN D V, KUSKOV O L. Phase diagram of H2O: thermodynamic functions of the phase transitions of high-pressure ices [J]. Solar System Research, 2010, 44(3): 202–222. doi: 10.1134/S0038094610030044 [47] BARTELS-RAUSCH T, BERGERON V, CARTWRIGHT J H E, et al. Ice structures, patterns, and processes: a view across the icefields [J]. Reviews of Modern Physics, 2012, 84(2): 885–944. doi: 10.1103/RevModPhys.84.885 [48] GONCHAROV A F, STRUZHKIN V V, SOMAYAZULU M S, et al. Compression of ice to 210 gigapascals: infrared evidence for a symmetric hydrogen-bonded phase [J]. Science, 1996, 273(5272): 218–220. doi: 10.1126/science.273.5272.218 [49] LOUBEYRE P, LETOULLEC R, WOLANIN E, et al. Modulated phases and proton centring in ice observed by X-ray diffraction up to 170 GPa [J]. Nature, 1999, 397(6719): 503–506. doi: 10.1038/17300 [50] BENOIT M, BERNASCONI M, FOCHER P, et al. New high-pressure phase of ice [J]. Physical Review Letters, 1996, 76(16): 2934–2936. doi: 10.1103/PhysRevLett.76.2934 [51] CAVAZZONI C, CHIAROTTI G L, SCANDOLO S, et al. Superionic and metallic states of water and ammonia at giant planet conditions [J]. Science, 1999, 283(5398): 44–46. doi: 10.1126/science.283.5398.44 [52] SUN J M, CLARK B K, TORQUATO S, et al. The phase diagram of high-pressure superionic ice [J]. Nature Communications, 2015, 6(1): 8156. doi: 10.1038/ncomms9156 [53] FRENCH M, DESJARLAIS M P, REDMER R. Ab initio calculation of thermodynamic potentials and entropies for superionic water [J]. Physical Review E, 2016, 93(2): 022140. doi: 10.1103/PhysRevE.93.022140 [54] HERNANDEZ J A, CARACAS R. Superionic-superionic phase transitions in body-centered cubic H2O ice [J]. Physical Review Letters, 2016, 117(13): 135503. doi: 10.1103/PhysRevLett.117.135503 [55] KNUDSON M D, DESJARLAIS M P, LEMKE R W, et al. Probing the interiors of the ice giants: shock compression of water to 700 GPa and 3.8 g/cm³ [J]. Physical Review Letters, 2012, 108(9): 091102. doi: 10.1103/PhysRevLett.108.091102 [56] CELLIERS P M, COLLINS G W, HICKS D G, et al. Electronic conduction in shock-compressed water [J]. Physics of Plasmas, 2004, 11(8): L41–L44. doi: 10.1063/1.1758944 [57] MILLOT M, HAMEL S, RYGG J R, et al. Experimental evidence for superionic water ice using shock compression [J]. Nature Physics, 2018, 14(3): 297–302. doi: 10.1038/s41567-017-0017-4 [58] GLATTER V O, KRATKY O. Small angle X-ray scattering [M]. London: Academic Press, 1982. [59] MCWILLIAMS R S, DALTON D A, MAHMOOD M F, et al. Optical properties of fluid hydrogen at the transition to a conducting state [J]. Physical Review Letters, 2016, 116(25): 255501. doi: 10.1103/PhysRevLett.116.255501 [60] WEIR S T, MITCHELL A C, NELLIS W J. Metallization of fluid molecular hydrogen at 140 GPa (1.4 Mbar) [J]. Physical Review Letters, 1996, 76(11): 1860–1863. doi: 10.1103/PhysRevLett.76.1860 [61] CELLIERS P M, MILLOT M, BRYGOO S, et al. Insulator-metal transition in dense fluid deuterium [J]. Science, 2018, 361(6403): 677–682. doi: 10.1126/science.aat0970 [62] KNUDSON M D, DESJARLAIS M P, BECKER A, et al. Direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium [J]. Science, 2015, 348(6242): 1455–1460. doi: 10.1126/science.aaa7471 [63] FORTOV V E, ILKAEV R I, ARININ V A, et al. Phase transition in a strongly nonideal deuterium plasma generated by quasi-isentropical compression at megabar pressures [J]. Physical Review Letters, 2007, 99(18): 185001. doi: 10.1103/PhysRevLett.99.185001 [64] MOCHALIN V N, SHENDEROVA O, HO D, et al. The properties and applications of nanodiamonds [J]. Nature Nanotechnology, 2012, 7(1): 11–23. doi: 10.1038/nnano.2011.209 [65] MARSHALL M C, GORMAN M M, POLSIN D N, et al. Diamond formation in double-shocked epoxy to 150 GPa [J]. Journal of Applied Physics, 2022, 131(8): 085904. doi: 10.1063/5.0082237 [66] MONSHI A, FOROUGHI M R, MONSHI M R. Modified Scherrer equation to estimate more accurately nano-crystallite size using XRD [J]. World Journal of Nano Science and Engineering, 2012, 2(3): 154–160. doi: 10.4236/wjnse.2012.23020 [67] WATKINS E B, HUBER R C, CHILDS C M, et al. Diamond and methane formation from the chemical decomposition of polyethylene at high pressures and temperatures [J]. Scientific Reports, 2022, 12(1): 631. doi: 10.1038/s41598-021-04206-7 [68] HARTLEY N J, BROWN S, COWAN T E, et al. Evidence for crystalline structure in dynamically-compressed polyethylene up to 200 GPa [J]. Scientific Reports, 2019, 9(1): 4196. doi: 10.1038/s41598-019-40782-5