An X-ray FEL laboratory as part of a linear collider design

This paper presents an X-ray Free Electron Laser laboratory (XFEL for short) as part of a Linear Collider facility. After presenting the overall scheme, we discuss the advantage of using a low RF frequency linac (preferably a superconducting one) as the driver of an XFEL. The parameter range with respect to pulse structure, photon wavelength and brilliance values is presented as well as schemes of distributing the train of several thousand electron bunches per RF pulse to many different users. Main technical challenges and proposed solutions are discussed.