  This note presents optimization results for an injector with a
super-conducting gun for the cw operation of the European XFEL, the
corresponding start-to-end simulation calculations for the beam transport to
the undulators and SASE calculations of the X-ray intensities for the
achievable photon energies.
  The optimizations for an injector with a super-conducting gun are done mainly
for an already experimentally shown accelerating gradient of 40 MV/m. Different
working points with respect to transverse emittance and bunch length are chosen
to see whether the lower transverse emittance of the longer bunches survives
the necessary stronger bunch compression to achieve comparable peak currents in
the undulators. Also, results for possible further improvement of the gun
gradient to 50 MV/m and a modified transverse laser profile (truncated
Gaussian) are shown.
  The S2E calculations are taking into account all relevant collective effects,
including a thorough treatment of the impact of the so called Micro-Bunching
Instability. For that purpose, tracking with the real number of particles is
done, with a resolution in space and time fine enough to calculate instability
growth model-free.
