Konstantin Sukharnikov Scientific instrumentation

A hobby. An independent overview compiled from public sources by a science and space enthusiast. I am not involved in these missions or facilities; my own work is detector electronics at European XFEL. My projects →

Facility · X-ray lasers

FERMI

Externally seeded free-electron laser for extreme-ultraviolet and soft X-rays (harmonic cascades; FEL-1 converted to EEHG)

Status
Operating
Location
Basovizza (Trieste), Italy
Operator
Elettra Sincrotrone Trieste
Next
FERMI 2.0 — schedule and funding not announced

Summary

The first externally seeded free-electron laser open to users: FEL-1 covers 100–20 nm (single-stage harmonic cascade), FEL-2 20–4 nm (two-stage cascade). The linear accelerator was designed for about 1.5 GeV and reached 1,663 MeV in May 2025 (description, milestones). First lasing was in December 2010; FEL-2 opened to users in June 2016. Beamlines: DiProI, EIS-TIMEX, EIS-TIMER, LDM, MAGNEDYN and TeraFERMI.

Now as of 9 Nov 2026

The first phase of the FERMI 2.0 upgrade is complete: FEL-1 now uses the EEHG seeding scheme, and the linac energy has been raised to 1.5 GeV at 50 Hz (above 1.65 GeV at 10 Hz). FERMI 2.0 aims to extend the range into the "water window" and beyond, and to shorten the pulses to the core-hole lifetime of light elements (FEL2024, L. Giannessi). No schedule for the next phases has been published. The neighbouring Elettra storage ring has been shut down for its upgrade since July 2025 (see Elettra 2.0); the sources found do not confirm whether FERMI has been running for users throughout.

Key dates

  1. Dec 2010First lasing (seeded, 260 nm)done
  2. Jun 2016FEL-2 opens to usersdone
  3. 2024FEL-1 converted to EEHG (FERMI 2.0, phase 1), by Augustdone
  4. May 2025Linac reaches 1,663 MeVdone

Timeline

  1. Aug 2024FEL2024: status of FERMI 2.0 — JACoW