Why SwissFEL?

Switzerland is a small country but nvertheless, it contributes to the global wealth of knowledge appreciably well. This fact attracts many brilliant minds and innovative companies from all over the world to Swiss universities and research centers. Preserving this reputation of excellence implies keeping pace with the state of the art in science and technology. Particularly in fields of such high economic impact like materials science, chemistry and biology, it will be crucial to have access to the new scientific horizons made available by a free-electron laser.
With their unrivalled brightness and short pulse duration, Free Electron Lasers (FEL) will support progress towards the development of faster and smaller magnetic storage devices, a better understanding of catalytic materials for chemistry, bring along dramatically improved imaging techniques for bio-molecules in drug discovery and provide new insights into poorly understood materials that are technologically appealing:

One key feature of SwissFEL is its extraordinary brightness. Brightness or brilliance means high intensity combined with tight focusing and spectral purity. The brightness of X-FELs will surpass that of the most advanced synchrotron light sources by 12 orders of magnitude (one thousand billions times more). This significant increase in brightness will enable the imaging of the structure of proteins sitting in the membrane of cells, even from tiny microcrystals. While synchrotrons need relatively large crystals for protein imaging and membrane proteins are so hard to crystallize, the superior brilliance of SwissFEL will remove the requirement of growing large crystals, and cell membrane proteins like receptors and channels will reveal their long held secrets.


FEL's additional key feature is their short pulse duration. In chemistry, for instance, which deals with the reactivity of molecules due to their geometrical and electronic structure at the nanoscale, ultrafast processes still remain virtually unexplored. How does the poisonous carbon monoxide convert into less harmful carbon dioxide on a nanometer size platinum plate? How does the magnetic state of an iron atom in a protein affect its ability to bind oxygen and deliver it to distant tissue? For decades, scientists have been unable to find answers to such questions. SwissFEL can now be of help in their inquiries and help to develop nanometer size magnets for storage devices and new superconducting materials.

How short a time are 20 femtoseconds?

A SwissFEL pulse will be as short as 20 femtoseconds. This is a staggeringly short time! Within 20 femtoseconds even light travels only a distance of six microns. This is as small as one tenth of the thickness of a human hair and thus far beyond what the human eye can distinguish.

Why we need hard X-Rays to see atoms?

One of the fundamental laws of optics states that, when imaging an object with electromagnetic radiation (light), the smallest structures that can be resolved are the size of the wavelength of the light used. Hence, in order to image atoms, radiation with a wavelength as short as one tenth of a nanometer is needed. This is exactly the wavelength of the so called hard X-rays. A look at the electromagnetic spectrum reveals what kind of light can be used to see different structures occurring in nature.

SwissFEL Science Case

SwissFEL Science Case.gif

Utrafast Phenomena at the Nanoscale: Science opportunities at the SwissFEL X-ray Laser

SwissFEL Science Case Download

Further information

  • Film explaining SwissFEL

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