SwissFEL

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SwissFEL is the free-electron X-ray laser that was inaugurated at the Paul Scherrer Institute (PSI) in December 2016 .

The SwissFEL design is optimized to generate X-ray pulses in the wavelength range from 1  Å to 70 Å. The system configuration is relatively compact with a total length of almost 740 meters. The project is being built and operated to complement the European XFEL . Construction work for the SwissFEL began in spring 2013. After the building was completed, the installation of the technical components began in early 2015. The first pilot experiments were carried out in 2017. The first ARAMIS beamline was put into operation in 2018 . The second ATHOS beam line is to follow by autumn 2020.

ARAMIS delivers very high-energy, short-wave X-ray light with which one can easily follow how atoms behave during a fast-moving process. ATHOS delivers softer, lower-energy X-ray light to watch atoms and molecules form new chemical bonds. Overall, the construction cost around 275 million Swiss francs.

Location

The SwissFEL was built near the PSI site in the Würenlinger Wald. There, the temperature fluctuations and vibrations are particularly low, which simplifies operation: the temperature in the jet channel must not deviate from the ideal 24 degrees Celsius by more than 0.1 degrees, because otherwise the slightest material expansion will distort the measurement results or completely thwart experiments. This is another reason why large parts of the long building were covered with earth and gravel. Thus, at the same time created a lean lawn - habitat that serves as a natural habitat for many endangered plants and animals.

functionality

The SwissFEL essentially consists of four components: an electron source, a linear accelerator, an arrangement of undulators and measuring stations. With a pulsed laser, electrons are released from a copper disk. The cloud of these electrons is accelerated and held together by an electric field. They are directed into the linear accelerator, which further accelerates the electrons with alternating voltage at a high frequency. The electrons now fly through a stretch of alternating dipole magnets , the undulator: This forces them on a slalom course. With every change of direction, the electrons emit X-ray light . This creates an X-ray light beam with laser-like properties that can be used for experiments in the measuring stations.

The X-ray beam has an output of up to 10 gigawatts and is pulsed extremely quickly: up to 100 flashes per second, each lasting only 1 to 60 femtoseconds. The pulses are so bright that they can be used to create films of the movements of the atoms and molecules. There are only four other X-ray laser systems of a comparable size in the world.

Areas of application

With X-ray lasers like the one from SwissFEL, for example, new materials for electronics can be researched in order to further advance miniaturization in this area. You can follow the course of catalytic reactions at the atomic level in order to optimize them and thus improve resource efficiency in environmental technology or the chemical industry. Biomedical scientists can observe in detail the structure of vital proteins and their reactions to substances in order to develop new drugs.

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Individual evidence

  1. ↑ Christian Speicher: Swiss X-ray Laser: A Business Card for the Research Area In: Neue Zürcher Zeitung of December 5, 2016
  2. ↑ Start of construction in the Würenling forest . Retrieved September 17, 2014.
  3. ↑ SwissFEL ready for assembly . Retrieved March 8, 2016.
  4. ↑ First experiment successfully carried out at SwissFEL . Retrieved January 24, 2018.
  5. ↑ First Pilot Experiment at SwissFEL-Alvra . Retrieved January 24, 2018.
  6. ↑ PSI Annual Report , 2017 edition, p. 11
  7. ↑ Hollywood in the Würenlinger Wald. Retrieved April 25, 2019 .
  8. ↑ a b You don't notice perfect beam lines. Retrieved April 25, 2019 .
  9. ↑ a b c The Swiss X-ray free electron laser SwissFEL. Retrieved April 25, 2019 .
  10. ↑ a b SwissFEL - the new large system of the Paul Scherrer Institute. Retrieved April 25, 2019 .
  11. ↑ Walter Hagenbüchle: The Paul Scherrer Institute conducts the kind of research that needs staying power. Neue Zürcher Zeitung, October 14, 2018, accessed on April 25, 2019 .