X-ray generation under oblique incidence of femtosecond laser pulses with kHz pulse repetition rate on a metal foil with irregular relief

The possibility of improving the efficiency of X-ray generation under the interaction of femtosecond laser pulses (exhibiting high repetition rate and subrelativistic intensity) with a thin copper foil by changing the angle of incidence of the laser radiation is studied both experimentally and theoretically. The brightness of such an X-ray source in the conducted experiments considerably exceeded that of a conventional X-ray tube. The structure of the target surface before and after interaction is described in detail, and specific features of the influence of this structure on absorption of laser pulses are analyzed.