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The New Highlight in Switzerland's Research Infrastructures

Welcome to the Website of the SwissFEL, Switzerland's X-ray free-electron laser currently being built at the Paul Scherrer Institute.

The SwissFEL is based on a novel technology holding exceptional promises for diverse areas of scientific research. Serving our society's modern trends "smaller, faster, more complex", SwissFEL will provide unprecedented insights into structures as small as an atom and into phenomena as fast as the vibrations of molecular bonds. It will also reveal the secrets behind the inner complexity of technologically relevant materials

Current News

5. November 2015

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New EU project: Guiding light for the world’s brightest light sources

EUCALL will build bridges between major laser and X-ray research centres: For the past half-century, two special kinds of light have changed the landscape of research. Advanced visible-spectrum optical lasers have propelled studies into ultrafast processes, new materials, telecommunications, and many other fields, while intense X-rays produced at synchrotrons have helped image tiny structures and otherwise invisible parts of matter, enabling huge leaps in biochemistry, pharmacology, and materials science. New developments have enhanced the generation of X-rays at optical-laser and accelerator facilities, resulting in the creation of large international research centres. The European Union is now funding a 7 million-euro effort to bring these research centres together through the European Cluster of Advanced Laser Light Sources (EUCALL) project.Read the full Story

26. October 2015

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Put in perspective

Researchers from the Paul Scherrer Institute PSI have succeeded in using commercially available camera technology to visualise terahertz light. In doing so, they are enabling a low-cost alternative to the procedure available to date, whilst simultaneously increasing the comparative image resolution by a factor of 25. The special properties of terahertz light make it potentially advantageous for many applications, from safety technology to medical diagnostics. It is also an important tool for research. At PSI, it will be used for the experiments on the X-ray free-electron laser SwissFEL. The terahertz laser developed at PSI is currently the world’s most intensive source of terahertz light. Read the full story

12. October 2015

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New methods to generate short and high-power X-ray Free-Electron-Laser pulses

State-of-the-art X-ray Free-Electron-Laser (XFEL) facilities like SwissFEL are able to provide radiation pulses with pulse powers of a few tens of gigawatts and pulse durations of several tens of femtoseconds and shorter. There is, however, a strong demand in research fields such as bioimaging and nonlinear optics to obtain higher radiation powers and shorter pulses than in standard facilities. In this context, we have developed two new methods able to generate terawatt-attosecond XFEL pulses. Both proposals are based on superradiance, a regime with quadratic growth of the radiation power and a shortening of the spike while it slips into unspoiled (good-beam) regions of the bunch. Read more

22. September 2015

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Laser arrival time measurement and correction for the SwissFEL lasers

To probe ultrafast processes at SwissFEL it is crucial that the pump laser, used at the end stations, arrives in time with the generated X-ray pulses. For fs resolution pump probe experiments a path-length change of few-hundred nanometers already affects the measurement quality. The length of SwissFEL and the total propagation path of the pump laser light to the experiment is in the scale of several hundred meters, which makes this task challenging. Read more

24. August 2015

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Umbrella MoU Signed by 14 Parties

The Memorandum of Understanding of the Umbrella Collaboration was signed by 14 parties: ALBA, DESY, Diamond Light Source Ltd, Elettra, EMBL Heidelberg, ESRF, European XFEL, HZB, ILL, Instruct Academic Services Ltd, KIT, PSI, STFC and SOLEIL. Read more

17. August 2015

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Terahertz laser light focused to the extreme

There are limits to how short a flash of light can be – in both time and space. Researchers from the Paul Scherrer Institute (PSI) have now succeeded in reaching these physical limits and producing the smallest possible flash. Read more

10. July 2015

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High-Precision Vertical Linear Translation for Offset Mirrors

The horizontal and vertical offset mirrors are key optical elements for the SwissFEL ARAMIS Beamline. The offset mirrors for example, are used to deflect and steer the x-ray beam into one of the end stations. Read more

8. June 2015

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PSI-DESY Collaboration Delivers First Photonics Component for SwissFEL

The Photon Beam Intensity Gas (PBIG) monitor arrived at PSI at the end of May, and will be one of the first photonics components to be installed in the new SwissFEL facility. Read more

19. May 2015

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Beam Stoppers for SwissFEL

On the 5th of May the two beam stoppers were installed in the SwissFEL tunnel. These two blocks are made out of copper, recycled lead, steel and concrete blocks and weight 60 tons each. These stoppers are placed in front of both Aramis and Athos undulator lines. Read more

19. March 2015

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Table-top soft x-ray lasers based on high-order harmonic generation (HHG)

Table-top soft x-ray lasers based on high-order harmonic generation (HHG) deliver routinely linearly polarized light. Many advanced applications including magnetic imaging would profit from a HHG source delivering in addition circular polarized light. In one of our recent work we present now an approach which provides intense soft x-ray radiation of high ellipticity. This source has given us the opportunity to realize the first magnetic dichroism experiment on a nickel sample at 18 nm (67 eV) with a table-top HHG source.Read more

17. February 2015

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Prospective studies for SwissFEL experiments done at the SLS FEMTO station

L. Rettig et al, Phys. Rev. Lett. 114, 067402 – Published 13 February 2015, DOI: PhysRevLett.114.067402 For many years, PSI researchers have been testing experimental methods that will provide insights into novel materials for electronic devices. Using a special trick to make the Swiss Light Source (SLS) at PSI generate light with similar properties to that of PSI's x-ray laser SwissFEL, the researchers were able to demonstrate that the experiments planned for SwissFEL are possible and they are now building an experimental station at SwissFEL. Read the full Story

13. February 2015

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Successful start of the series production of the C-band accelerating structures for SwissFEL

A total of 104 C-band accelerating structures will be needed for SwissFEL. Each of these structures is about 2 m long and consists out of 113 copper cells that are manufactured with micrometer precision using ultra-precision diamond machining, which results in mirror-like surfaces. The main components are the couplers at the input and the output of the structure, and the copper disks. For both, couplers and disks, the series production was successfully launched at the end of 2014. Since then the Dutch company VDL and TEL Mechatronics in Trübbach, Switzerland, delivered already many sets of couplers and accelerating disks, respectively.Read more

16. January 2015

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Terahertz wavefront control for extremely bright THz bullet

The brightness of a light source defines its applicability to nonlinear phenomena in science. The SwissFEL laser group has now overcome one of the two principal technological hurdles to produce bright pulses in the Terahertz range (0.1-5 THz). Read more

December 2014

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Record low emittance for compressed bunches at the SwissFEL Injector Test Facility

The emittance of the electron beam is crucial for Free-Electron Laser (FEL) facilities: it has a strong influence on the lasing performance and on the total length of the accelerator. The emittance of the whole bunch, called projected emittance, is a general indicator of the electron beam quality. However, the key beam parameter for FELs is the slice emittance, i.e. the emittance measured for individual slices along the bunch length. In practice, both slice and projected emittance need to be optimized. A procedure to measure and minimize the projected and slice emittance was developed and implemented at the SwissFEL Injector Test Facility, a 250 MeV accelerator that was in operation between 2010 and 2014 to demonstrate the feasibility of the SwissFEL design. Read more

13. October 2014


SwissFEL Injector Test Facility: Summary of Experimental program achievements until decommissioning

The SwissFEL Injector Test Facility (SITF) at the Paul Scherrer Institute completed its four-year experimental program on October 13, 2014. Since its official inauguration in August 2010, the injector plant has fulfilled its purpose as a development facility for beam dynamics studies and a test bed for diagnostics developments, both in view of the realization of the SwissFEL. Read more

October 2014

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A time-dependent order parameter for ultrafast photoinduced phase transitions

The exploration of the interaction of structural and electronic degrees of freedom in strongly correlated electron systems on the femtosecond time scale is an emerging area of research. One goal of these studies is to advance our understanding of the underlying correlations, another to find ways to control the exciting properties of these materials on an ultrafast time scale. So far a general model is lacking that provides a quantitiative description of the correlations between the structural and electronic degrees of freedom.Read more

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7 Å resolution in protein two-dimensional-crystal X-ray diffraction at Linac Coherent Light Source

Membrane proteins arranged as two-dimensional (2D) crystals in the lipid environment provide close-to-physiological structural information, which is essential for understanding the molecular mechanisms of protein function. Previously, X-ray diffraction from individual 2D crystals did not represent a suitable investigation tool because of radiation damage.Read more

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Launch of the "SwissFEL in Virtual Reality" Model

On the 10.06.2014 the new SwissFEL in Virtual Reality Model was launched. The SwissFEL in a virtual reality model was realized with the help of the AGORA SNF funding project. SwissFEL in a virtual reality is a video game like device with whom SwissFEL researchers want to attract the general public, and especially groups usually less interested in research (i.e. people fancying videogames, entire families: parents in their thirties, with children between 8 and 15). The virtual model fosters communication of cutting edge research to the general public by explaining and guiding through the concept of Switzerland’s new cutting edge research facility through the new Virtual Reality Model in a playful way. Read more

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First beam from the SwissFEL electron gun

6.06.2014 The new 3 GHz photocathode gun will provide the electron bunches for SwissFEL and has recently been installed in the SwissFEL injector test facility. There, it replaced the CTF2-gun 5, borrowed from CERN. The new gun is capable now of operation with 100Hz repetition frequency and a higher field on cathode and improved field symmetry.Read more

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Investigating ultrafast magnetization dynamics with a table-top femtosecond XUV laser

The study of ultrafast dynamics initiated by a femtosecond laser pulse is a hot topic. Many questions, such as the angular momentum transfer during the laser-matter interaction are yet unanswered which calls for advanced metrology. In order to investigate ultrafast transient dynamics in magnetic materials we have now implemented a new diagnostic scheme at our extreme UV high-harmonic (HHG) beamline which is based on the Transverse Magneto-Optic Kerr effect (T-MOKE). Read more

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Large European R&D project holds its third annual meeting on the epn campus in Grenoble/France

Large research infrastructures are built on making the latest in technology for use in scientific experiments available to scientists. This often requires joint R&D efforts, and the CRISP project is bringing together eleven main players from across Europe to address four key technology areas for the big science of tomorrow. CRISP was launched in October 2011; the third annual meeting was the occasion to review the current status of the project, present some of the major accomplishments, and to coordinate the work for the last months of the project. Read more

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Coherent femtosecond radiation up to 300 eV

State of the art table-top high-order harmonic (HHG) sources driven by an intense femtosecond are routinely used to produce coherent soft x-ray pulses up to a photon energy of 100 eV. It is clear that many applications would benefit from higher photon energies, such as seeding a free electron laser, imaging of biological tissue in the water window (285 eV-530 eV) or the investigation of ultrafast magnetization dynamics in transition metals and rare earth elements with absorption edges in the range >100 eV. Motivated by such applications, the SwissFEL laser group has now extended the maximum photon energy from a table-top laser-driven source from 100 eV up to 300 eV (4 nm) Read more



The workshop of the PSI engineering department (AMI) recently completed the manufacturing of the high brightness electron source that will drive SwissFEL. The first characterization of the 2.5 cells RF photo cathode is in excellent agreement with the design values without applying a post-manufacturing tuning. Read more

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First lasing at the SwissFEL Injector Testfacility

On the 15th of January 2014, first lasing was achieved in the SwissFEL injector test facility. This is a great success on the way towards SwissFEL, the future hard x-ray free-electron laser that is currently under construction at PSI. It proves the successful functioning of many key components together in a larger system as required for SwissFEL. Furthermore, this is the very first operation of a free-electron laser in Switzerland. Read more


Installation of SwissFEL Undulator Prototype in the Injector Test facility

On December 5th, the 17 tons SwissFEL undulator prototype (In-vacuum Undulator U15) has been successfully moved from the Undulator lab (SLS) to the SwissFEL Injector Test Facility (SITF). The commissioning of the U15 prototype with electron beam is an important step to validate the U15 design and also to detect possible improvements before full series production. Read more

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Photon Arrival and Length Monitor (PALM).

The accurate measurement of the time between a pump laser pulse and a FEL probe pulse is vital to the success of the future SwissFEL facility, which plans to use pump-probe science as a cornerstone of its activities. This measurement, along with the measurement of the time-profile of the FEL pulse, is the goal of the new device designed and tested by the Photonics group at SwissFEL called the Photon Arrival and Length Monitor (PALM). Using a technique called THz-streaking, the device looks at electrons photoionized by FEL radiation and accelerated by an oscillating THz field generated by a laser to determine when during the field’s oscillation the electron was generated from a gas. Read more

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52 MV/m in C-band structure

This summer, the first 2 m long C-band accelerating structure for SwissFEL was installed in the high power test stand at PSI. The goal was to verify that the accelerating structure can handle the high accelerating fields of around 28 MV/m that are needed for SwissFEL. At such high accelerating fields, sporadic break-downs are unavoidable, and a second goal was to confirm that the number of break downs is at a level that is acceptable for SwissFEL. Read more

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First beam: XUV laser meets Terahertz laser

Two new coherent photon sources, combined on a single laser table, have been built by the SwissFEL laser group and are operated successfully since several weeks by now. While the first type of laser delivers intense radiation in the Terahertz region at around 0.3 THz (i.e. 1 mm wavelength), the second laser source is a table-top, laser-driven XUV source based on high-order harmonic generation. It delivers photon energies up to 120 eV (i.e. 10 nm wavelength) in fully coherent XUV bursts of a few tens of femtosecond or even attosecond duration. Read more

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First measurement campaign of the U15

The first measurement campaign of the U15 (the undulator prototype for the SwissFEL project) shows that electron trajectory straightness (measured with a dedicated Hall Probe bench) can be optimized beyond the micrometer level over the full operational range. Read more


Magnetisation controlled at picosecond intervals

A terahertz laser developed at the Paul Scherrer Institute makes it possible to control a material’s magnetisation at a timescale of picoseconds (0.000 000 000 001 seconds). In their experiment, the researchers shone extremely short light pulses from the laser onto a magnetic material, where the magnetic moments – “elementary magnets” – were all aligned in parallel. The light pulse’s magnetic field was able to deflect the magnetic moments from their idle state in such a way that they exactly followed the change of the laser’s magnetic field with only a minor delay. The researchers report on their results in the journal Nature Photonics. Read more

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SwissFEL Milestone Party 3rd of July 2013

On the 3rd of July the SwissFEL Milestone Party took place, after the official foundation stone ceremony of PSIs new large scale facility. Around 250 guests defied the rain to see the revelation of the milestones at the SwissFEL construction site. Afterwards a nice dinner was offered in the OASE. The event was accompanied by a jazz quartet.

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X-ray Laser: A novel tool for structural studies of nano-particles

Development of analysis method for X-ray laser scattering data.

Prominent among the planned applications of X-ray free electron laser facilities, such as the future SwissFEL at the Paul Scherrer Institute, PSI, are structural studies of complex nano-particles, down to the scale of individual bio-molecules. A major challenge for such investigations is the mathematical reconstruction of the particle form from the measured scattering data. Read more

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Federated Identity Management for Research Infrastructures FIM4R at PSI

On the 20th to the 21st of March 2013 the Federated Identity for Research Infrastructures FIM4R took place. This workshop in the fifth in a series, that started in summer 2011, to investigate Federated Identity Management for Research collaborations. For more information read here…

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CRISP 2nd annual Meeting at PSI

On the 18th to the 20th of March 2013 the CRISP annual meeting was held at PSI. The meeting was a great success. The talks given by experts from different facilities gave an inspiring view of progress made within the different collaboration topics of the CRISP project read more... More than 100 participants from the different CRISP partner facilities participated at the meeting. We are grateful for the excellent contributions which were made.

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SwissFEL project approved by Swiss Parliament.

An important political milestone for the realization of the new SwissFEL facility was reached in December 2012, the Swiss Parliament approved the SwissFEL project. The legally valid building permit for SwissFEL arrived at the end of January 2013. Which means that the project can start! First works on the building site already initiated.

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Establishment of European Free-Electron Laser Collaboration.

On the 31.05.2012 ten European research centres, including PSI agreed on a long-term close collaboration in the field of free-electron lasers and accelerator-based short-pulse sources. With combined efforts, the technologies and methods will be further developed and implemented for operation and use of these novel research facilities, thus creating a unique top level research infrastructure for science in Europe, offering optimal experimental conditions for a wide range of applications. Today, in the margins of the ERF workshop “Socio-economic Relevance of Research Infrastructures”, this collaboration agreement was signed at DESY by representatives of all institutes. Read more


Swiss-Swedish Partnership in Accelerator, Photon and Neutron Science.

The Paul Scherrer Institute (PSI) and the École Polytechnique Fédérale de Lausanne (EPFL) have signed an agreement with three leading Swedish research institutions covering technology development for the next generation of free-electron lasers and collaboration in photon and neutron science. The agreement promises a world of new research opportunities in materials, energy, environmental and life sciences. Read more


PSI-SwissFEL signs MoU with STFC on the 29th of November 2011.

With their signature, representatives of the PSI and the STFC, today, formalized the cooperation between the SwissFEL and STFC. The main focus will be on the establishment of a collaborative research effort to enable the exploitation and expansion of the scientific capabilities of the future SwissFEL project at PSI. Read more

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PSI-SwissFEL cooperates within the EU research network CRISP of eleven new European research infrastructures.

CRISP is a partnership which builds collaborations and creates long-term synergies between research infrastructures on the ESFRI (European Strategy Forum on Research Infrastructure) Roadmap in the field of physics, astronomy and analytical facilities to facilitate their implementation and enhance their efficiency and attractiveness. Read more

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The PaNdata Open Data Infrastructure project (PaNdataODI) started in October 2011.

PSI-SwissFEL is part of PANdata ODI. PaNdata-ODI will develop, deploy and operate an Open Data Infrastructure across the participating facilities with user and data services which support the tracing of provenance of data, preservation, and scalability through parallel access. It will be instantiated through three virtual laboratories supporting powder diffraction, small angle scattering and tomography

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Workshops on hard X-Ray Instrumentation with the SwissFEL

The SwissFEL team of the Paul Scherrer Institute invites you to attend two workshops on hard X-ray instrumentation at the SwissFEL X-ray Free Electron Laser facility 12.9.11 and 21.11.11, at the University of Bern. more information here

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Nicolas Kurti European Science Prize for a SwissFEL Scientist

The Nicholas Kurti European Science Prize, sponsored by Oxford Instruments, is intended to recognise and promote outstanding achievements of young scientists in the field of physical sciences research and to support their career development. In 2011 this prestigious price was awarded to Prof. Dr. Mathias Kläui, head of the SwissFEL Nanoscale Spindynamics Group more information here

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A prestigious FEL award for an outstanding scientist at the Paul Scherrer Institute

At the 32nd International Free Electron Laser Conference in Malmö, Sweden, the Prize Committee decided to award the prestigious 2010 FEL prize to Dr. Sven Reiche for “his outstanding contributions to the advancement of the field of Free-Electron Laser science and technology”. more information here


Lights on…. Inauguration of the SwissFEL Injector Test Facility

An important milestone for the realization of the new SwissFEL facility was reached on the 24th of August 2010, when the core of the new SwissFEL facility was set into operation at the Paul Scherrer Institute. Guest of Honour, Bundesrat Didier Burkhalter pressed the red button, and the SwissFEL Injector Test Facility produced its first electron beam. For more information see current news from PSI.

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SwissFEL Injector Conceptual Design Report

The SwissFEL Injector Conceptual Design Report is completed and published in August 2010.
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SwissFEL Conceptual Design Report

The SwissFEL Conceptual Design Report is completed and published at the end of July 2010.

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First Beam at SwissFEL Injector Test Facility

The technical development of the project has reached another milestone: In the SwissFEL injector test facility the first electron beam from the gun has been extracted and accelerated to 5 MeV on the 12th of March 2010.

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SwissFEL Included in Strategic Planning ETH Board

An important decision has been taken towards the realization of SwissFEL at PSI. The ETH Board has discussed PSI's proposal at its board meeting, beginning of March 2010, and has given unanimously its support by including the project in the strategic planning of the ETH Domain.

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SwissFEL Science Case

Based on the SwissFEL science workshop series and with input from the PSI departments and international review committees, the science case has now been completed and published. The document is available as a PDF file.

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