Materials under extreme conditions at Omega and NIF

Transcription

1 Materials under extreme conditions at Omega and NIF Gilbert Rip Collins D. Hicks, R. Rygg, J. Eggert, R. Smith, P. Celliers, H. Park D. Spalding, D. Bradley, D. Swift, S. McWilliams, D. Braun, D. Kalentar, M. Bastea, Y. Ping, P. Patel, B. Heeter, J. McNanny, J. Hawriliak (LLNL) OLUG April, T. Boehly, U. of Roch R. Hemley Carnegie Institute, R. Jeanloz U.C. Berkeley, T. Duffy Princeton, B. Militzer Berkeley Y. Gupta Washington State J. Wark Oxford P. Loubeyre CEA, This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344

2 Hot Jupiters Mega-Jupiters up to 13 Jupiter masses Super-Earths 342 extrasolar planets have been discovered through March 2009, more on the way HD b Gilese 876d Extrasolar planets Earth Mars Uranus Neptune Mercury Launch of Kepler mission, March 2009 Venus Jupiter Saturn Our Solar System Brown Dwarfs: 80 to 13 Jupiter Masses 2 2

3 Understanding planetary evolution requires knowledge of the material properties at extreme conditions Temp (K) Planetary upper limit Only lasers can reach these states ~Jupiter 10 Jupiter mass Stars Large Icy satellites ~Uranus Earth to super- Earth cores Pressure (Mbar) D. Stevenson 3

4 Lasers are redefining condensed matter, chemistry, plasma, and nuclear science Omega and NIF allow us to explore the most extreme conditions in planets and low mass stars Temperature (K) Soon we will study P > 1 Gbar shocks, P> 10 s Mbar for Ramp compression Iron Fluid Ramp Pressure (Mbar) Stixrude, 2008 Starts Oct

5 Lasers are redefining condensed matter, chemistry, plasma, and nuclear science Pulse shape =>ultra-high pressure plasma and solid-state experiments Total power (TW) With Shock precom pressed D-> ~5 g/cc Ramp Soon we will study P > 1 Gbar shocks, P> 10 s Mbar for Ramp compression Temperature (K) Iron Fluid Ramp Time (ns) Pressure (Mbar) Stixrude,

6 We determine shock and particle speed with a shock speedometer (VISAR), temperature with pyrometer laser Targets Standard U s (standard) VISAR U p U s sample ρ o (U s ) = ρ(u s -U P ) P = ρ 0 U s U P 1 E = P(1/ ρ o -1/ ρ) 2 3 equations, 5 unknowns (Us, Up, P, ρ, E) -> need to Measure 2 of these 6

7 We determine shock and particle speed with a shock speedometer (VISAR), temperature with pyrometer laser Targets Standard U s (standard) VISAR U p U s sample Pyrometer Temperature is measured separately from pressure, density. 7

8 Carbon, a principal constituent of Neptune, is thought to have a complicated solid and liquid structure 100 Neptune K, 3-7 Mbar Diamond? Martin et al, PRL98 8

9 By measuring shock velocities very accurately we determine pressure and density to a few percent We have compressed diamond by ~ 3x Polymeric fluid To plasma Hicks, & Boehly, PRB 08 Liquid-solid mix & conducting (Bradley) Solid insulator 9

10 Temperature was measured on decaying shocks This unveiled the melt curve from 6 to 11 Mbar Pressure Use decaying shock to Map high P-melt curve Decaying single shock (6-40 Mbar) hν Distance Melt curve stays nearly flat from 6-11 Mbar T (10 3 K) 10 Single-shock Hugoniot (Eggert, sub 09) Fluid phase Pressure (Mbar) J. Eggert 10

11 Reflectivity measurements show Carbon melts from the diamond phase to a liquid metal Melt along 1-shock Hugoniot Diamond melts to a liquid conductor 30 T (10 3 K) Single-shock Hugoniot (Eggert, sub 09) Reflectance solid 10 Pressure (Mbar) VTR Kereley Sesame Liquid fraction Pressure (Mbar) Shock speed (Km/s) 40 Bradley, 05 In fact several materials become conducting upon melt (MgO, SiO2, LiF,..) This is not what one would expect from simple condensed matter theory 11

12 Finally this carbon metallic fluid phase is also polymeric up to 20 Mbar and 30kK Dulong-Petit Hicks PRL 06 Eggert sub. to Nature 09 Both SiO 2 and C exhibit a high heat capacity due to dissociation and bonding reconfiguration up to 20 Mbar This is not predicted by Ab-initio models 12

13 To generate colder dense states with lasers, just tune laser intensity versus time Laser ramps use x-ray drive stepped samples Ramp laser intensity to produce shockless compression Free surface velocity vs time Edwards, et al. (PRL 04) Smith, et al. (PRL 06) Bradley, et al. 08 Eggert et al. (SCCM 07) Velocity histories are used to determine P-rho Wave-profile analysis is used to determine C l,stress,rho (Maw,Rothman,05, Eggert 06) R. Smith

14 We measured the stress-density of diamond to 8 Mbar with ramp compression Ramp waves keep the sample ~cool and solid (until plastic heating ) Ramp compression shows diamond is stable and strong to 8Mbar 30 T (10 3 K) 20 Fluid carbon Shock Stress (Mbar) Ramp Pressure (Mbar) Bradley PRL 08 This allows us to measure the properties of many solids to ~ TPa pressures 14

15 Jupiter is thought to contain H and He at 10 s of Mbar, what happens to H or He at those conditions? He drop formation? 2 Mbar 5300 K 77 Mbar K Ice crystals Fluid H 2 + He Phase transition region? Fluid metallic H + He Ices? Possible core of iron/rock? C. J. Hamilton How How do do we we study study these these light light fluids fluids at at such such high high density? 15

16 Most previous high pressure-temperature experiments on hydrogen focused on the Hugoniot Particular attention on H due to its importance in astrophysics and ICF Hugoniot T(K) H 2 Conducting fluid Fluid H 2 Jupiter P+e Pycno-nuclear Hugoniot: Nellis et al DaSilva et al Knudson et al Boehly, et al Hicks et al Glenzer et al 100 Solid H 2 Metal H P(Mbar) Loubeyre, 06 Scientists have measured P, rho, T and the insulating to conducting transition in the WDM regime to ~ Mbar pressures on the Hugoniot 16

17 Coupling diamond cells to laser shocks enables access to ultra-high density states for He, H 2, He+H 2 Particular attention on H due to its importance in astrophysics and ICF Precompressed shocks sample H 2 Conducting fluid Jupiter quartz plate T(K) P+e 1000 Fluid H 2 10 kbar 50 kbar ~isentrope.6 Mbar Solid H 2 Metal H P(Mbar) Pycno-nuclear NIF Diamond cell Visar Loubeyre 06 The technique has been demonstrated on Omega to 200 GPa, and is expected to scale to 10+ TPa on NIF (Eggert PRL 08, Jeanloz PNAS 07, Lee JCP 06, Loubeyre JHP 06) 17

18 He/H2 data give insight to the insulator-conductor transition of the mixture Reflectivity and T for He/H 2 Mix is Between He and H Molecular H 2 Reflectivity Data shows Jupiter/Saturn Are homogeneous At least to here Temperature (ev) Recent data and theory suggest He/H2 likely miscible at 1 Mbar/30kK This may have important implications for ICF 18

19 What next? Hydrogen Phase space Log Temperature (K) Log density (g cm -3 ) 19 19

20 What next? Hydrogen Phase space Log Temperature (K) Log density (g cm -3 ) 20 20

21 What next? Hydrogen Phase space Cold fuel 1 Kg/cc Log Temperature (K) Hot spot 10 8 K Convergent experiments (Smalyuk, Rygg) Explore key items for ignition Log density (g cm -3 ) 21

22 Advanced diagnostics are key for the next generation experiments dynamics, chemistry, band structure.. High resolution imaging 17.5 KeV image of shock in Quartz 500 μm Qz Omega CARS to determine bonding (Bolme) Shock Diffraction to determine structure (Eggert, Hawriliak, Wark, Lorenzana ) Park, Boehly Hi-res interferometry (Celliers) X-ray Scattering/absorption for Melt, Chemistry (Yaakobi, Hicks) 22 22

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