  We propose a use of the self-seeding scheme with single crystal monochromator
to produce high power, fully-coherent pulses for applications at a dedicated
bio-imaging beamline at the European X-ray FEL in the photon energy range
between 3.5 keV and 5 keV. We exploit the C(111) Bragg reflection
(pi-polarization) in diamond crystals with a thickness of 0.1 mm, and we show
that, by tapering the 40 cells of the SASE3 type undulator the FEL power can
reach up to 2 TW in the entire photon energy range. The present design assumes
the use of a nominal electron bunch with charge 0.1 nC at nominal electron beam
energy 17.5 GeV. The main application of the scheme proposed in this work is
for single shot imaging of individual protein molecules.
