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In this paper, enhancement in x-ray emission and reduction of kinetic energy of ions from low density foam plasma is demonstrated by performing experiment and hydrodynamic simulation. The plasma is produced by irradiation of solid gold and gold foam targets (densities 0.2 g/cc, 0.13 g/cc and 0.1 g/cc) at intensities in the range of 4×10 13 -1×10 14 W cm −2 . Time resolved x-ray emission is measured by an x-ray streak camera with 10 ps resolution. The x-ray flux measured by the streak camera from low density gold foam shows a 13% enhancement in comparison to solid gold in the spectral range >0.8 keV and above. Decrease in velocity of ions is observed in low density gold foam. In solid gold, thermal ions peak velocity is 31×10 4 m s −1 and spread in narrow energy width, however, in case of 0.1 g/cc, peak velocity reduces to 6×10 4 m s −1 towards target normal and emitted in broad energy range. Shadowgraphy results also provide evidence of narrower expansion of plasma from solid gold. However, total ion flux from low density gold foam is comparable to ion flux of solid gold indicating the process of volumetric absorption.

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An advanced type of hydrodynamic stable plasma targets with homogeneous distribution of plasma parameters has been proposed for application in experiments on heavy ion stopping in plasmas and relativistic laser based particle acceleration. Plasma was created via x-ray heating of polymer aerogels with a mean density 10 3 times lower than that of solid matter. Hydrodynamic and radiation properties of low-density polymer aerogels heated by x-rays, which were generated due to laser interaction with a gold hohlraum, have been investigated experimentally and numerically. In experiments carried out at the PALS laser facility in Prague, the parameters of the hohlraum based soft x-ray source and the fraction of x-ray energy absorbed by foam layers have been measured. The results of these experiments and numerical simulations show that the x-ray heat process occurs via propagation of supersonic radiation driven heat waves. The measured heat wave velocity of 10 7 cm s −1 allows one to estimate the plasma temperature reached as 25 eV. The hydrodynamic stability of x-ray heated plasma layers has been demonstrated by means of an optical streak camera viewing the plasma expansion process. Simulations of the foam heating process denote rather homogeneous distribution of the plasma temperature and density in the x-ray heated plasma layer and sharp plasma boundaries. The investigated features of such plasma targets are a great advantage for experiments with heavy ion and relativistic laser beams.