Abstract
A numerical simulation was conducted of the generation of short-wavelength radiation in a gas target driven by a short laser pulse, taking into account the diffraction of the laser beam and the generated fields. It is shown that a sequence of attosecond x-ray pulses of about 100 as duration is formed in the far field of diffraction. The feasibility of extracting a single attosecond pulse out of the total generated field employing pinholes is demonstrated.