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In comparison

The European XFEL and FLASH

The DESY facility FLASH is a smaller version of the future European XFEL. Both light sources generate X-ray radiation, which differs essentially in its wavelength.

FLASH and the European XFEL rely on the same operating principle: Electrons are first brought to high energies in an accelerator and then made to radiate high-intensity X-ray flashes.

The light from the two facilities differs mainly in its wavelength (colour). Whereas around four nanometers (four billionths of a metre) are reached at FLASH, the European XFEL will generate laser light with more than 80 times shorter wavelengths. Using the light from FLASH, scientists can already make out single molecules; at the European XFEL, they will be even able to observe their atomic structure.

FLASH has been in operation for experiments since 2005 and is being developed even further. Today already, new experimental methods enabling completely novel experiments are being devised and exploited at FLASH. These methods will be refined in the coming years and will then also be available for research at the European XFEL.

FLASH is a facility of the Helmholtz research centre DESY. It is located on the DESY site in Hamburg. The European XFEL will be around 10 times larger than FLASH. The facility is under construction between the DESY site and the town of Schenefeld and will operated by an independent research organization, the European XFEL GmbH.

More about FLASH

Abbreviation for European X-ray Free-Electron Laser Free-Electron Laser in Hamburg
Start of commissioning 2016 2004
Length of the accelerator 1.7 kilometres 0.15 kilometres × 11
Length of the facility 3.4 kilometres 0.3 kilometres × 11
Number of accelerator modules 100 7 × 14
Maximum electron energy 17.5 billion electron volts (17.5 GeV) 1 billion electron volts (1 GeV) 17.5
Minimum wavelength of the laser light 0.05 nanometre
(of the order of an atom)
4.1 nanometres
(of the order of a molecule)
× 1/82
Number of undulators (magnet structures for light generation) 3, upgradeable to 5 1
Number of experiment stations 6, upgradeable to 10 5 × 2
Location Hamburg and Schenefeld Hamburg
Operator European XFEL GmbH DESY

The European XFEL in international comparison

Besides the European XFEL in Germany, next-generation light sources also exist in Japan and in the USA. The European XFEL will be the last of the three facilities to take up research operation; its performance, however, will make it outstanding.

X-ray laser facilities are being constructed all over the world: LCLS in California, SACLA in Japan, and the European XFEL in Germany. The operating principles of these facilities are very similar. Electrons are first accelerated to high energies and then made to generate high-intensity X-ray laser light. Whereas LCLS and SACLA rely on conventional accelerator technologies, however, the European XFEL will operate at minus 271 degrees Celsius using superconducting technology.

Peak brilliance in comparison
The peak brilliance of free-electron lasers exceeds the brilliance of the most modern synchrotron radiation sources by several orders of magnitude.
European XFEL
Click on the image to see it full size.

Superconduction allows the creation of an electron beam of especially high quality composed of many electron bunches aligned one behind the other. This enables the European XFEL to generate many more light flashes per second than the other two facilities. The number of usable light flashes is increased as well. Certain experiments will thus only be possible at the European XFEL, and others can be carried out much faster. The higher number of electron bunches also allows more experiment stations to be operated simultaneously.

Abbreviation for Linac Coherent Light Source SPring-8 Angstrom Compact Free Electron Laser European X-Ray Free-Electron Laser
Location California, USA Japan Germany
Start of commissioning 2009 2011 2016
Accelerator technology normal conducting normal conducting superconducting
Number of light flashes per second 120 60 27 000
Minimum wavelength of the laser light 0.15 nanometres 0.08 nanometres 0.05 nanometres
Maximum electron energy 14.3 billion electron volts (14.3 GeV) 6-8 billion electron volts (6-8 GeV) 17.5 billion electron volts (17.5 GeV)
Length of the facility 3 Kilometer 750 Meter 3.4 Kilometer
Number of undulators (magnet structures for light generation) 1 3 3, upgradeable to 5
Number of experiment stations 3-5 4 6, upgradeable to 10
Peak brilliance
[photons / s / mm2 / mrad2/ 0.1% bandwidth]
2·1033 1·1033 5·1033
Average brilliance
[photons / s / mm2 / mrad2/ 0.1% bandwidth]
2.4·1022 1.5·1023 1.6·1025