News & Scientific Highlights

Not a joke: on 1st of April 2016 the Photon Single-Shot Spectrometer (PSSS) got delivered fully assembled and installed already to the front end of SwissFEL. It will measure the photon spectral information in every single shot for the Aramis beamline not only for the users, but also as a direct feedback to the machine during formation of the lasing process.

JUNGFRAU (adJUstiNg Gain detector FoR the SwissFEL Aramis User station) is a two dimensional hybrid pixel detector for photon science applications at free electron lasers and synchrotron light sources. The JUNGFRAU 0.4 prototype presented here is specifically geared towards low-noise performance and hence soft X-ray detection. With an extremely low noise of less than 30 electrons it enters a field formally reserved for SSD’s and CMOS imagers allowing single photon resolution down to a photon energy of 500eV.

The installation of the linear accelerator (Linac) progresses very well. This week, the last girder of the so-called “Linac 1” was installed in the SwissFEL tunnel. The entire C-band accelerator consists out of Linac 1, Linac 2, and Linac 3, and a total amount of 104 accelerating structures. Meanwhile, 38 accelerating structures are installed in the SwissFEL tunnel. The assembly work on the remaining Linac modules will take place until end of September of this year. By then it is planned to finish the installation of all Linac modules in the SwissFEL tunnel.

On the 25th of January, the first "completed" undulator has been transported to its final position in the SwissFEL tunnel. The 1064 permanent magnets of this undulator where shimmed to the sub-micrometer level and the magnetic profile has been carefully measured for the full gap range. Twelve of such undulators will be installed until October 2016!

Mirrors are key elements to distribute and shape the Xray beam generated by the undulators of the SwissFEL facility. They are essential tools to guide and focus the light according to the specific users requirements and should do this without noticeable effects on the beam quality. A quantitative measure is the quality of the beam wavefront.

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.

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.

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.