X-ray spectroscopic study of nonequilibrium laser produced plasma in porous targets of low average density

New experimental results on laser irradiation (I ≤ 10 14 W/cm 2 , λ = 1.053 μm) of low-density fibrous agar are presented. X-ray spectrometers with spherically bent mica crystals were used for measuring with high spectral resolution the line spectra of multicharge ions. Detailed analysis of the measured spectra made it possible to determine the temperature of electrons and ions in hot plasma created in laser irradiated low-density samples in dependence on average material density and average intensity within a focal spot. Significant difference between ion and electron temperatures is found for the whole range of experimental conditions.