In this paper we present Hugoniot data for plastic foams obtained with laser-driven shocks. Relative equation-of-state data for foams were obtained using Al as a reference material. The diagnostics consisted in the detection of shock breakout from double layer Al/foam targets. The foams [poly(4-methyl-1-pentene) with density $130>\rho >60\mathrm{mg}∕{\mathrm{cm}}^3$] were produced at the Institute of Laser Engineering of Osaka University. The experiment was performed using the Prague PALS iodine laser working at $0.44\mu \mathrm{m}$ wavelength and irradiances up to a few ${10}^{14}\mathrm{W}∕{\mathrm{cm}}^2$. Pressures as high as $3.6\mathrm{Mbar}$ (previously unreached for such low-density materials) where generated in the foams. Samples with four different values of initial density were used, in order to explore a wider region of the phase diagram. Shock acceleration when the shock crosses the Al/foam interface was also measured.

• Received 16 August 2005

DOI:https://doi.org/10.1103/PhysRevE.73.047401