Energy, temporal, and spatial characteristics of vacuum ultraviolet radiation emitted by a laser plasma

The angular distribution of the radiation emitted by a laser plasma and the coefficient ζ representing the conversion of laser radiation of wavelength λ = 1.06 μm into vacuum ultraviolet radiation were determined for Al and Pb targets by using laser radiation power densities of 10⁸–10¹⁰ W cm^-2. Estimates were obtained for the maximum conversion coefficients: ζ = 0.65 for Al and 0.75 for Pb. The results obtained were compared with those reported by other authors. The emission duration of the plasma radiation was measured in different spectral intervals of the ultraviolet range. High-energy photons were observed in this radiation: they indicate that the emission spectrum of the laser plasma deviates from thermal at energies hν ≈ 1 keV. The experimental results were compared with theoretical calculations.