Compton scattering spectrum from laser compressed Fermi-degenerate beryllium. The width of the Compton feature is sensitive to density and its relative intensity is sensitive to the ion temperature.
Phase diagram of hydrogen. Physical regimes are indicated with solid lines showing the plasma coupling parameter and the electron degeneracy parameter . For , the plasma freezes into a bcc Coulomb solid. The melting curve of is also indicated for . The dashed curve shows the dissociation and ionization boundaries in the low density gas. Above , hydrogen is fully ionized. The Jupiter isentrope is shown by the heavy solid line. The regions probed by single, double, and triple shock experiments on deuterium are indicated with dotted lines. Filled squares show the near isentropic compression data of Fortov et al. (Ref. 9) suggesting a plasma phase transition in hydrogen. The single and double shock helium points of Nellis et al. (Ref. 42) are indicated with open squares. Finally, the hashed region outlines the locus of the shocked states achieved by Eggert et al. (Ref. 13) from precompressed He targets.
Comparison of between theory (solid lines) and laser shock wave experiments (symbols). Helium was exposed to extreme temperatures and pressure that are relevant for planetary interiors. The colors represent different precompression ratios. The ability to precompress samples statically before launching the shock is an important experimental improvement that allows to probe deeper in the giant planet interiors. Good agreement between theory and experiment is found for the higher precompressions.
Schematic interior view of Jupiter, based on Militzer et al. (Ref. 11). Running along the left in black are pressures and temperatures from their model at three locations, as well as the core mass estimate . The transition from molecular hydrogen to liquid metallic hydrogen ( is continuous. Running along the right in gray are these same estimates from Guillot (Ref. 43).
A comparison of theoretical mass-radius curves for gas giant planets and 40 observed transiting planets, using the models from Fortney et al. (Ref. 24). The majority of these planets orbit at distances of only 0.02–0.05 a.u. from their parent stars, while the Earth orbits at 1 a.u. (by definition). The -axis is mass in Jupiter masses, and the -axis radius in Jupiter radii. The top two solid black curves are for pure H–He, 4.5 Gyr old, giant planets at 0.02 and 0.045 a.u. from the Sun (the Earth-Sun distance is 1 a.u.). The thick dashed-dotted curve also shows models at 0.045 a.u., but with of heavy elements in a core. A mass-radius curve for pure water planets is also shown. Gray diamonds are, left to right, Uranus, Neptune, Saturn, and Jupiter. Black diamonds with error bars are the transiting planets. Curves of constant bulk density (in g ) are overplotted in dotted gray.
Resolution tests obtained with 60 keV x rays produced by a short pulse irradiated W-wire.
60 keV radiograph of a shock-compressed iron target.
Left: profiles of terrestrial super-Earths. The family of planets with have a similar Fe/Si ratio as Earth. The highest internal is 1.56 Mbars (156 GPa). The different phase transitions in the mantle are shown in dashed lines ranging from olivine (ol), wadsleyite (wd) and ringwoodite (rw), perovskite (pv) and magnesiowusite (wu), and postperovskite (ppv) and wu. The discontinuities are caused by the boundary layers at the top and bottom of the mantle. The mantles of super-Earths with masses larger than are mostly composed of , compared to the dominance of on Earth. Right: ternary diagram for a planet. The radius of a planet with each mixture is shown in color with the color bar spanning the radius of the smallest (a pure Fe planet with ) and largest (a —pure planet with ) super-Earth. The shaded region shows the unlikely compositions that can form a super-Earth from solar nebula condensation and secondary accretion constraints. A ternary diagram exists for every planetary mass value.
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