On the hot electrons and Kα x-rays generation in the intense laser interaction with silver targets

Intensity dependence of the conversion efficiency of laser energy into the energy of hot electrons is determined with the aid of measurements and modeling of Kα-photon yield from silver targets irradiated by relativistically intense subpicosecond laser pulses. We take into account intensity dependence of the effective hot electron temperature assuming the Wilks' scaling. The measurements reveal approximately the same values of the Kα yield from a silver foil of 10 μm thickness, attached onto aluminium or plexiglass substrates, at the intensities about 1018 W/cm2 and 2 × 1019 W/cm2. Intensity dependence of the Kα yield from the silver foil, calculated using determined conversion efficiency of laser energy into the energy of hot electrons, is in agreement with the measurements.