FERMI is a single-pass FEL user-facility designed to cover the wavelength range from 100 nm to 4 nm in the first harmonic. It uses a linear accelerator to generate a beam of relativistic electrons that is made to propagate through a long series of undulators. A conventional laser superposed to the electron beam in the first undulator (seeding) is utilized to induce coherent emission, which is exponentially amplified when the electrons propagate through the following undulator magnetic field. Among existing FEL sources FERMI is unique in many respects. The implemented seeded FEL scheme guarantees the generation of high transversely and longitudinally coherent pulses and the use of APPLE II-type undulators allows for variable polarization, from completely linear both horizontally and vertically to circular in both directions.

FERMI light source

Free Electron Laser

FERMI source implements two externally, seeded free electron lasers that will produce coherent, ultrafast pulses.
Read more about seeding

Facility Overview

FERMI, a 4th generation light source, is a linac based, single pass Free Electron Laser.

Conceptual Design Report

The FERMI Conceptual Design Report.
See the document



The Macro-activity Calendar.

Achievements & figures

Current beam parameters of FEL

Project Milestones

FERMI is under commissioning with external users and it is continuously improved and upgraded.
Milestone list


Papers published on conference proceedings and journals.
See the list


Related Links

Last Updated on Thursday, 25 February 2016 15:27