Experimental study of bremsstrahlung and characteristic radiation spectra from laser targets irradiated with ultrashort laser pulses with intensities of up to ∼1019 W/cm2

Results from experimental studies of bremsstrahlung and characteristic radiation spectra from laser targets irradiated with ultrashort laser pulses with intensities of up to ∼1019 W/cm2 are presented. The continuous spectra of hard X-ray emission from Ta and Al targets and the line spectrum of copper were measured. The temperature of fast electrons was obtained from the measured hard X-ray spectra, and the Kα radiation yield from Ta was measured. The energy conversion efficiency of laser radiation into the copper characteristic radiation was obtained from the measured yield of Kα radiation.