  In this paper we discuss extending the operating wavelength range of tunable
Regenerative Amplifier FELs to shorter wavelengths than current design
proposals, notably into the XUV regions of the spectrum and beyond where the
reflectivity of broadband optics is very low. Simulation studies are presented
which demonstrate the development of good temporal coherence in generic systems
with a broadband radiation feedback of less than one part in ten thousand.
