Paul Scherrer Institute Switzerland: PSI Inaugurates Free-electron X-ray Laser

Editor: Susanne Hertenberger

The PSI has inaugurated a free-electron X-ray laser (FEL). „SwissFEL“ is expected to drive new developments in the areas of energy, environment, information technology, and health.

Federal Councillor Johann Schneider-Ammann and PSI Director Joël Mesot push the red buttons.
Federal Councillor Johann Schneider-Ammann and PSI Director Joël Mesot push the red buttons.
(Source: Paul Scherrer Institute)

After three and a half years of construction, the Swiss Free Electron Laser (“SwissFEL”) at the Paul Scherrer Institute (PSI) was inaugurated in a ceremony attended by Swiss Federal President Johann Schneider-Ammann. This facility is an electron accelerator that produces high-brilliance, i.e. extremely intense and very short, pulses of X-ray light with laser properties. “SwissFEL is the most ambitious project that we ever realized at PSI”, said PSDI Director Joël Mesot, who opened the ceremony. A project made possible only through the dedication of all who worked on it, but also through the support from industry, which has supplied key components for the research facility, as well as from politics at all levels, from federal to cantonal and municipal.


Ultrafast processes

SwissFEL belongs to a new generation of X-ray light sources. Free-electron X-ray lasers generate very short pulses of X-ray light with the characteristics of laser light. With the X-ray laser, researchers will be able to observe extremely fast processes like the formation of new molecules in chemical reactions, determine the detailed structure of vital proteins, and clarify the precise composition of materials. The first pilot experiments are scheduled for 2017. So far, this type of research has been confined to only a few facilities worldwide. SwissFEL now provides researchers with an additional total of 5,000 hours of test time per year. The first pilot projects by so-called expert users will run in 2017 and are intended to test the interaction of the individual components.

The costs for the construction of the research facility amount to around 275 million Swiss francs and were largely funded by the federal government. The canton of Aargau also contributed to the financing with 30 million Swiss francs from its lottery funds. The facility itself is located in a 740-metre tunnel in the forest next to the PSI site and consists of four sections: In the first section, the injector, electrons are generated and pre-accelerated. A linear accelerator then brings the electrons to the required high velocity. The Undulators, magnets with alternating polarity, make up the third section, where electrons are forced onto a snake-like path on which they generate the X-ray light, whose radiation is then routed to the experimental facilities in the fourth section, where researchers from universities or industry can run experiments. The highly brilliant and ultrashort X-ray pulses enable researchers to visualize transient changes of atomic and molecular structures. Previously hidden ultrafast processes can now effectively be viewed step by step like in a film.

SwissFEL as a driver of innovation

As one of currently only four facilities of its kind in the world, SwissFEL will play an important role for international research. “Just like the Swiss Light Source SLS, SwissFEL will attract leading researchers from Switzerland and the whole world”, said the next speaker, Roger Falcone of UC Berkeley, with conviction. SwissFEL will help secure Switzerland’s position as a location for innovation. The subsequent panel discussion centred around the question what needed to be done to maintain and expand Switzerland’s leading position in research and innovation. The commonly shared position was that needed are the right framework conditions for the construction of research infrastructures like SwissFEL, close cooperation between research and industry – which for example should be promoted by the Innovaare innovation park located at the PSI –, a commitment to fundamental research as the foundation for disruptive ideas, and courage to support innovative ideas from the beginning.

Federal Councillor Schneider-Ammann

In his subsequent speech, Federal Councillor Johann Schneider-Ammann also emphasised the importance of research and innovation for Switzerland as a whole, comparing the free-electron X-ray laser with the Gotthard Base Tunnel, which was also opened in 2016: “Both tunnels are considered technical masterpieces, both tunnels embody Swiss know-how, and both tunnels are ground-breaking.” He said Switzerland placed great value on excellent infrastructure, which was one of the reasons why the country regularly achieves top positions in innovation rankings. Then project leaders Rafael Abela and Hans Braun led the guests through the inauguration ceremony. “After many years of planning, construction, and installation, a new SwissFEL era dawns at PSI: The time of scientific harvest is at hand”, said Abela. As the highlight of the ceremony, Schneider-Ammann and Mesot together pushed the “red button” and thus symbolically put SwissFEL into operation.

Paul Scherrer Institute

Project Leaders SwissFEL: H.H. Braun & R. Abela, 5232 Villigen,