RESUMO
The rate of laser ablation at irradiances of approximately 2 x 10{14} W cm{-2} of solid iron has been measured using the transmission of a neonlike zinc x-ray laser at 21.2 nm through thin iron targets. Ablated iron becomes transparent to the x-ray laser flux, enabling the thickness of unablated material and hence the rate of ablation to be measured from time resolved x-ray laser transmission.
RESUMO
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 mg/cm3] 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 microm wavelength and irradiances up to a few 10(14) W/cm2. Pressures as high as 3.6 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.
