Characterization of compact bright soft X-ray source based on picosecond laser plasma.

Radiation emission of silicon and aluminum plasmas produced by 40-ps laser pulses with peak intensity above 1014 W/cm2 was studied. High-resolution soft X-rayspectra of H-like and He-like ions were analyzed to determine plasma parameters. We compared the line shape of resonance transitions and their intensity ratios to corresponding dielectronic satellites and the intensities of the intercombination lines of He-like ions with the results of model calculations. Such comparisons gave average values of the electron number density Ne=(1-1.9)×1021 cm-3 and the electron temperature Te=460–560 eV for Si plasmas and about 560 eV for Al plasmas produced by the first and the second laser harmonics. The plasma size is about 100 μm. According to our estimations, more than 1012 photons were produced within the resonance line spectral width and in the solid angle 2π during the total decay period. [ABSTRACT FROM AUTHOR]