Study of physical processes in laser-irradiated porous targets of different microstructure

New results obtained in experiments on laser irradiation (${\rm I}=10^{14}$ W/cm$^{2}$, ${\rm \lambda} =1.055 {\rm \mu}$m) of low-density (1-30 mg/cm$^{3})$ fibrous and foam-like materials are presented and discussed. The effect of low-density material microstructure of irradiated samples on physical processes in high-temperature plasma was investigated. Using a variety of complementary X-ray and optical methods the pronounced effect of material microstructure on the parameters and dynamics of produced plasma was found