Efficient ion beam generation in laser interactions with micro-structured targets

The maximum ion energy and acceleration efficiency have to be increased for practical applications of intense ion beams produced by intense short laser pulses incident on a thin foil. For this aim, we propose to use foil with a microscopic structure on the front size. We have prepared such targets by depositing a monolayer of polystyrene nanospheres of a size comparable to laser wavelength on a thin foil. The damage threshold of the produced targets is found experimentally above 3.5 × 10 9 W/cm 2 for a nanosecond pedestal and above 10 11 W/cm 2 for femtosecond prepulses.