Absolute Equation-of-State Measurement for Polystyrene from 25 to 60 Mbar Using a Spherically Converging Shock Wave

Author(s): Doeppner, T.; Swift, D.C.; Kritcher, A.L.; Bachmann, B.; Collins, G.W.; Chapman, D.A.; Hawreliak, J.; Kraus, D.; Nilsen, J.; Rothman, S.; Benedict, L.X.; Dewald, E.; Fratanduono, D.E.; Gaffney, J.A.; Glenzer, S.H.; Hamel, S.; Landen, O.L.; Lee, H.J.; LePape, S.; Ma, T.; MacDonald, M.J.; MacPhee, A.G.; Milathianaki, D.; Millot, M.; Neumayer, P.; Sterne, P.A.; Tommasini, R.; Falcone, R.W. | Abstract: We have developed an experimental platform for the National Ignition Facility that uses spherically converging shock waves for absolute equation-of-state (EOS) measurements along the principal Hugoniot. In this Letter, we present one indirect-drive implosion experiment with a polystyrene sample that employs radiographic compression measurements over a range of shock pressures reaching up to 60 Mbar (6 TPa). This significantly exceeds previously published results obtained on the Nova laser [R. Cauble et al., Phys. Rev. Lett. 80, 1248 (1998)] at a strongly improved precision, allowing us to discriminate between different EOS models. We find excellent agreement with Kohn-Sham density-functional-theory-based molecular dynamics simulations.