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 PolFEL free electron laser project comprises 185 MeV cw-linac furnished with ASG electron gun and 4 Rossendorf-like cryomodules. The beam diagnostics system, besides bringing the beam to undulators, inverse Compton scattering interaction point, and finally to the dump, system is dedicated to metallic superconducting photocathodes development, in particular to gun performance characterization. Bunch length will be measured in the injector section, behind the bunch compressor, and in each linac branch, behind the wakefield linearizer at the undulator entrance. The bunch length is evaluated from sub-THz coherent Cherenkov radiation spectral distribution. Radiation emitted from a punched radiator will be analyzed with Martin–Puplett interferometer and measured with a broadband detector, both located on the breadboard at linac. A prototype will be preliminary measured with laboratory sub-THz source at IOE-MUT and subsequently at the Solaris linac with 0.5 GeV electrons.

SOLARIS injector LINAC is designed to efficiently fill the electron storage ring. The injection currently takes place at 540 MeV, two times per day. After the accumulation of electron current, the energy is ramped up inside the ring to 1.5 GeV via two active RF cavities. Top-up injection would be of extreme benefits for user operation, therefore here we present a simulation study for the design of a new injector that would make this possible in the future. The major constraint for the simulation campaigns has been the space available in the existing LINAC tunnel. The idea is to replace the current machine (or modifying it) without infrastructural interventions in terms of tunnel expansion. Performed studies demonstrate that the best solution is provided by a Hybrid S-band/C-band LINAC. Simulations have been performed using different codes and results are shown here. Finally, a new machine working at 1.5 GeV would also pave the way to further diagnostic and/or experimental beamlines for particles and radiation solely based on the LINAC. In particular, one of the main goals is to achieve bunch compression below the picosecond level and low-emittance beams for a future short-pulse facility or a Free Electron Laser.