European X-ray Free Electron Laser

  • One of the most powerful X-ray machines ever built has officially opened in the German city of Hamburg.
  • The facility, which has cost more than a billion euros to build, will be used to study the detailed structure of matter, atom by atom.
  • It is called the European X-ray Free Electron Laser (XFEL).
  • Scientists say the way it shines light on targets will permit, for example, chemical bonds to be filmed in the instant that they are made or broken.
  • The researchers anticipate fundamental discoveries that lead to new medical treatments and novel materials, to name just two possibilities.
  • The XFEL will begin operations with 11 nations as members of its consortium.
  • Britain, which has supplied equipment to the facility, is expected to sign commitment papers to join the group before the end of the year.

How it Works:

  • It works by accelerating bunches of electrons to almost light-speed, before then throwing them down a slalom course controlled by a system of magnets, known as undulators.
  • As the electrons bend and turn, they emit flashes of X-rays; and as the particles interact with this radiation, they also bunch even tighter.
  • Their compact configuration not only intensifies their light emission but gives it coherence as well. In essence, the X-rays are “in sync” and have the properties of laser light.
  • The beam will penetrate and detail at the atomic scale whatever is put in its path.
  • This could be the protein molecules that drive our bodies or the catalyst materials used to produce industrial chemicals.
  • Many nations around the world use circular machines called synchrotrons that do a very similar job.
  • But the light generated by the XFEL is about a billion times brighter than those facilities. What also sets the XFEL apart is the super-fast time structure in its flashes.
  • The machine will deliver trillions (1,000,000,000,000) of X-ray photons in a pulse lasting just 50 femtoseconds (0.000,000,000,000,05 sec), and it can repeat this 27,000 times a second.
  • It allows for time-resolved investigations that are beyond what is possible in standard synchrotrons. For example, scientists will use a jet to stream their samples in front of the beam, priming them with another laser so that chemical reactions are triggered at just the right moment to be caught by the pulses.
  • The conventional X-ray light sources also use pure crystals of the biological molecules they want to study. These can be very difficult to make – impossible in some cases.
  • Germany not only hosts the XFEL, it has provided most of the funding and the technology. The other members are Russia, Denmark, France, Hungary, Italy, Poland, Slovakia, Spain, Sweden and Switzerland.

Source: BBC

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