The project of PolFEL free electron laser comprises 185 MeV cw-linac furnished with ASG electron gun and 4 Rossendorf-like cryomodules. Magnetic lattice has been designed applying alike air cooled quadrupole magnets. FODO quadrupoles in undulator section differ with trimmed coils. A variety of dipoles has been designed: 14 – degrees air and water cooled rectangular dipoles are used for low and high energy bunch compressors. 17 - degrees dipoles guide the beam towards a dump. The design of these dipoles bases on identical yoke, furnished with adequate coils and vacuum chambers. 45- degrees water cooled dipoles form a transfer section between FEL and Inverse Compton Scattering parts of the linac. Quadrupole poles design assumed parasitic multipoles strengths less than 10-4 relative to the main one. Dipoles field was assumed uniform within 10-4 of B0. Yokes and poles designs have been performed using 2D FEMM code and refined in 3D with Radia. Manufacturing of yokes and coils will be achieved in NCBJ workshop. Currently, the quadrupole prototype has been built and will be mechanically, electrically and magnetically verified.

The electrons, which passed the undulators in a linac-driven Free Electron Lasers, could be utilized for additional radiation generation in an Inverse Compton Scattering process (ICS). The PolFEL, facility, currently in preparatory phase in NCBJ, is planned to be equipped with ICS system, to generate continuous (10kHz repetition rate) pulses train of hard X-ray radiation, in addition to THz-, VUV- and IR-light produced in FEL process. Taking into account the principles of Compton scattering, we designed the interaction chamber to assure head-on collision of electrons and optical photons and an X-ray detection system. To simplify the setup, we designed to use similar type of laser source for ICS system, as for photocathode excitation. The energy of generated X-rays, calculated on the basis of laser and linac parameters are in range between 115 keV and 1.9 MeV. The maximum number of X-ray photons is estimated to reach about 3x106 photons per mrad2 per second. In the paper, the design of ICS interaction chamber, detectors, and also calculated X-ray photon characteristics will be presented.