New Regimes of High Energy Density Materials Science*

The field of high energy density (HED) materials science refers to regimes involving energy densities greater than ~10¹² erg/cm³or pressures greater then ~1 Mbar. Such conditions can be found in planetary and exoplanet interiors [Nellis 1995, Seager 2007, Stewart 2012, Kraus 2015, Havel 2011, Valencia 2006]; planetary formation dynamics [Dahl 2010] and asteroid impact dynamics, [Korycansky 2000]; brown dwarf interiors [Burrows 2001]; and white dwarf envelopes. [Fontaine 2008; Dufour 2008] For example, the pressures inside of Jupiter can reach ~70 Mbar at the core. [Guillot 1999; Militzer 2016] Predictions suggest Super-Earth exoplanet core pressures can reach up to ~40 Mbar [Duffy 2019] and brown dwarf interior pressures can exceed ~1 Gbar [Burrows 2001]. These conditions can be accessed and explored experimentally on high energy, pulsed laser facilities. [Remington 2015]<br/> <br/>In this talk, a selection of experiments done on the NIF, Omega, and Omega EP lasers, on a variety of materials ranging from deuterium to lead, will be presented. Examples include high pressure equations of state (EOS) measurements using VISAR diagnostics; [Smith 2018; Celliers 2018, Fratanduono 2020] and time resolved x-ray diffraction to determine the lattice structure at high pressures. [Lazicki 2021, Rygg 2019] X-ray Thomson scattering (XRTS) has been used to characterize the ionization state, density, and temperature in high energy density (HED) plasma experiments. [Kraus 2016]. Radiography has been used to characterize the plasma conditions on the Hugoniot at pressures from 25 – 800 Mbar; [Döppner 2018, Kritcher 2020] and strength Rayleigh-Taylor instability experiments have been done in the solid state, plastic flow regime at high pressures and strain rates. [Krygier 2019, Park 2021] Water experiments at 1-4 Mbar have been done, and observed the superionic phase whereby the oxygen freezes into a crystalline fcc lattice, whereas the H remains itinerant. [Millot 2019] And finally, EXAFS experiments for measuring sample temperature at high pressure have been done on Omega, [Ping 2013] and are under development on NIF. [Coppari 2021]<br/> <br/><b>References:</b><br/> <br/>[Burrows 2001] Adam Burrows, Review of Modern Physics (2001).<br/>[Celliers 2018] Celliers, Peter M., Science 361, 677-682 (2018).<br/>[Coppari 2021] F. Coppari, in preparation (2021).<br/>[Dahl 2010] T.W. Dahl, Earth and Planetary Science Letters 295, 177–186 (2010).<br/>[Döppner 2018] T. Döppner, PRL 121, 025001 (2018).<br/>[Duffy 2019] Thomas S. Duffy, Frontiers in Earth Science 7, 23 (2019).<br/>[Dufour 2008] P. Dufour, Ap.J. 683, 978 (2008); ibid., Nature 450, 22 (2007).<br/>[Fontaine 2008] G. Fontaine, Ap.J. 193, 205 (1974).<br/>[Fratanduono 2020] D.E. Fratanduono, PRL 124, 015701 (2020).<br/>[Guillot 1999] T. Guillot, Science 286, 72 (1999).<br/>[Havel 2011] M. Havel, Astron. Astrophys. 531, A3 (2011).<br/>[Korycansky 2000] D.G. Korycansky, Icarus 146, 387 (2000).<br/>[Kraus 2016] D. Kraus PRE 94, 011202(R) (2016). <br/>[Kraus 2015] R.G. Kraus, Nature Geoscience 8, 269 (2015).<br/>[Kritcher 2020] A. L. Kritcher, Nature 584, 51 (2020); ibid., HEDP 10, 27 (2014).<br/>[Krygier 2019] A. Krygier, PRL 123, 205701 (2019).<br/>[Lazicki 2021] A. Lazicki, Nature 589, 532 (2021).<br/>[Militzer 2016] B. Militzer, JGR 121, 1552 (2016).<br/>[Millot 2019] M. Millot, Nature 569, 251 (2019); ibid., Nature Physics 14, 297 (2018)<br/>[Nellis 1995] W.J. Nellis, Science 269, 1249 (1995). <br/>[Park 2021] H.-S. Park, PoP 28, 060901 (2021).<br/>[Ping 2013] Y. Ping, PRL 111, 065501 (2013).<br/>[Remington 2015] B.A. Remington, PoP 22, 090501 (2015); ibid., PNAS, 116, 18233 (2019).<br/>[Rygg 2019] J. R. Rygg, RSI 91, 043902 (2020).<br/>[Seager 2007] S. Seager, Ap.J. 669, 1279 (2007).<br/>[Smith 2018] R.F. Smith, Nature Astronomy 2, 452 (2018); ibid., Nature 511, 330 (2014).<br/>[Stewart 2012] S.T. Stewart, Ap.J. 751, 32 (2012).<br/>[Valencia 2006] D. Valencia, Icarus 181, 545 (2006); ibid., Astron. Astrophys. 516, A20 (2010).<br/> <br/>*This work was performed under the auspices of U.S. DOE by LLNL under Contract DE-AC52-07NA27344.