National FEL Facilities

Since 2005, FLASH (Free Electron LASer in Hamburg) provides extremely bright, coherent and ultrashort pulses for a diverse and internationally recognized science community. FLASH produces laser light from the vacuum ultraviolet down to soft X-rays (47 – 6.5 nm) in ultra-short pulses of 10 – 50 femtoseconds duration. With an upgrade which has been completed in summer 2010 wavelengths below 5 nm are expected. The peak intensity of this novel X-ray source exceeds that of modern synchrotron radiation sources by many orders of magnitude opening up new fields of science for investigation and potential exploitation. For example, single-pulse imaging of in-vivo biological samples or nanostructures is a main area of application.

FERMI@Elettra, the VUV to soft X-ray Free Electron Laser at the Sincrotrone Trieste Laboratory, is quickly developing. It will turn into an operating FEL user facility with the first user experiments scheduled for the beginning of 2011. FERMI@Elettra is a new single-pass seeded Free Electron Laser radiation source providing time-synchronized ultrashort femtosecond pulses. As such, it will soon operate for a broad user community covering the wavelength range from 100 nanometres to 4 nanometres (from Vacuum-Ultraviolet to Soft X-rays) with high peak-brightness, ultrashort length, and transverse and longitudinally coherent light pulses.

HZB is pursuing an Energy Recovery Linac (ERL) as a next-generation X-ray light source. This type of accelerator combines the advantages of a LINAC and a storage ring allowing a higher average flux, brilliance and coherency of radiation. Other advantages of the source are: multi-user operation, ultra-short pulses and a lower energy spread. Flexibility is an additional aspect that makes the ERL-based light source very attractive.

The SPARX (Sorgente Pulsata Autoamplificata di Radiazione X) FEL project is aiming at the realization of a coherent light source of X-rays covering a wavelength range from 0.6 to 40 nm at the fundamental harmonic, and will be able to reach the Ångstrom-region using the third and fifth harmonics where high power is still produced.

The FEL project MAX FEL will be part of the MAX IV facility and is created in two phases. In the first phase a 3.5 GeV linac system is built to drive a Short Pulse Facility (SPF). Here, short highly brilliant X-ray pulses will be produced by spontaneous radiation in undulators. The linac system will thus be operated with an RF photocathode gun, which produces very low emittance pulses, and two bunch compressors suitable to drive either a short pulse facility or a FEL.

The new X-ray laser project, known as SwissFEL, will extend PSI’s unique platform of large interdisciplinary research facilities to serve international research teams from universities and from industry. The SwissFEL is an essential part of PSI’s strategic focus and will establish Switzerland’s leading position in scientific research for years to come. It will attract top scientists from all over the world and will enhance PSI’s acknowledged position as a world-class research institute. Furthermore, the new high-tech facility will provide an incentive for Swiss industry through which existing highly-qualified jobs can be maintained and new ones created.

In 2008, the UK Science and Technology Facilities Council (STFC) embarked on a project to examine the case for a New Light Source (NLS) facility. The following key science drivers were identified: • imaging nanoscale structures • capturing fluctuating and rapidly evolving systems • the study of structural dynamics underlying physical and chemical changes • ultra-fast dynamics in multi-electron systems.

Two optical paths transferring the beam to two experimental end stations will be installed in the first stage of the POLFEL operation. They represent the two branches of the scientific programme: basic science and technology. The light will be switched between them with the mirror installed behind the common photo diagnostics section. The first branch will be 25 m long and will be equipped with plane grating monochromator and will provide the micro-focused beam with energy resolution ΔE/E in the range of 10-5.

France is actively preparing the advance of fourth generation light sources, both from the machine and user sides. The French proposal of ARC-EN-CIEL (Accelerator Radiation Complex for Enhanced Coherent Extended Light) is combining the ultimate Free Electron Lasers seeded by high harmonics generation in gas in the VUV-soft X-ray domain, two ERL loops feeding undulators in spontaneous emission for the hard X-ray at 2 GeV and in the VUV and soft X-ray at 1 GeV, and a Free Electron Laser oscillation in the Extreme Ultra Violet region.