ELECTRON-BEAM OPTIMIZATION STUDIES FOR THE FERMI @ ELETTRA FREE-ELECTRON LASER

FERMI@Elettra is a single-pass free-electron laser, based on seeded high-gain harmonic generation scheme. Presently, the first phase of the project (covering the spectral range between 100 nm and 20 nm) is under commissioning. The free-electron laser performance depends on the quality of the electron beam used in the generation of the radiation. In the case of the FERMI linear accelerator, the quality of the electron beam is strongly influenced both by the wake-fields present in the accelerating sections and by possible misalignment of the various accelerator components. In order to investigate and compensate these effects, we performed a study, based on local trajectory bumps. We demonstrate that this approach significantly improves the electron-beam quality and, eventually, the free-electron laser performance.