  In the present work we report on the current progress of the recently
constructed GW attosecond extreme ultraviolet (XUV) source developed at the
Institute of Electronic Structure and Laser of the Foundation for Research and
Technology-Hellas (I.E.S.L-FO.R.T.H.). By the implementation of a
compact-collinear polarization gating arrangement, the generation of a
broadband, coherent XUV quasi-continuum produced by the interaction of a
many-cycle infrared field with a gas phase medium is achieved. The spectral
width of the XUV emission generated in Xenon, is spanning in the range of 17-32
eV and can support isolated pulses of duration in the range from 0.4 fs to 1.3
fs and pulse energy in the 1 {\mu}J level.Theoretical calculations, taking into
account the experimental conditions of this work, are supporting the
observations, offering also an insight regarding the temporal profile of the
emitted radiation. Finally, the high intensity of the produced XUV pulses has
been confirmed by investigating the two-XUV-photon double ionization process of
Argon atoms. The demonstrated results inaugurate the capability of the beamline
to produce intense isolated attosecond pulses towards their exploitation in
studies of non-linear XUV processes, attosecond pulse metrology and XUV pump
XUV probe experiments.
