Germany recently unveiled Europe's largest and most powerful X-ray laser. The installation can take as many as 27,000 images per second, giving great insight into the course of reactions in materials.
The unveiling was attended by ministers and other prominent guests from Europe, among others. This is also due to the fact that the installation was created in a collaboration between 11 European countries and soon 12, when the UK also joins in. Germany provided most of the funding and it is there (near Hamburg) that the device was commissioned. The Netherlands is not participating in the project. The preparation and construction of the facility took about eight years.
Record speed
The so-called X-ray Free Electron Laser (XFEL) produces extremely sharp and ultra-short pulses of light. The facility generates some 27,000 pulses per second, which is 200 times more than other X-ray lasers. This quantity is therefore a record, opening up new opportunities for research into materials and fast reaction processes.
With the help of specialised instruments, these X-rays provide new insights into the atomic details and extremely fast processes of the nano-world. For example, scientists can use these X-ray flashes to map the three-dimensional structure of biomolecules and other biological particles, faster and in more detail than has been possible to date.
Moreover, individual snapshots of particles produced by the laser can be assembled into a kind of 'molecular films'. Using these, researchers can study the progress of biochemical and chemical reactions - the basis for the development of new drugs and therapies or more environmentally friendly production methods and processes to extract energy from sunlight. Other applications can be found in the field of materials science with the development of new materials and substances, in the optimisation of media storage for computers or research into extreme matter found, for example, in exoplanets. "With the European XFEL, scientists will be at the forefront of worlds still unknown to us and be helped to find answers to questions surrounding humanity that make life better on our planet," said Olaf Scholz, the mayor of Hamburg.
The compound
The installation consists of several components. One is a source that produces electrons. A metal is bombarded with ultraviolet light. The electrons then make their way through a 1.7-km-long linear accelerator, where they emerge almost as fast as light, inside vibrating cavities in which microwaves transfer energy to the advancing electrons. Those vibrating cavities are superconducting and are yoked to - 271 °C for this purpose.
With the help of magnets, called the undulator, electrons are placed in a kind of slalom path after which the electrons produce X-rays. The interaction between the electrons and the radiation creates X-ray pulses in which all the light has almost the same phase.
Measuring instruments
In the XFEL, it is possible to direct the accelerated electrons to different undolators, each of which produces X-rays of a particular wavelength: two in the range 0.05 nm - 0.4 nm and one in the range 0.4 nm - 4.7 nm. With those different wavelengths, a broad spectrum of experiments is possible. Linked to the three undulators are six different instruments, each specialised for a particular type of research.
In such an experiment, X-ray flashes are shot at the material under investigation. The light that the material then emits is recorded with detectors and analysed, providing information about the properties of the material under investigation.
In the underground experiment hall, the first two instruments have been commissioned: the FXE instrument (which stands for Femtosecond X-Ray Experiments). This enables research on fast reactions and records 'molecular movies'. The other instrument is SPB/SFX (Single Particles, Clusters, and Biomolecules and Serial Femtosecond Crystallography) was developed to investigate the structure and transformation of biomolecules and other biological components, such as viruses and cell components.
The underground XFEL facility was built on the outskirts of Hamburg, from the existing DESY research centre towards Schenefeld. All in all, it cost around €1.2 billion. The video below shows just how big the facility is:
By: Kelly Bakker
Source + photos/video: XFEL/The Engineer
