Photo: DTU Physics

Large Danish imprint on world’s biggest X-ray laser

Physics Lasers Solar energy
On Friday, 1 September, the new European research facility European XFEL was inaugurated in Hamburg, Germany. One of the two instruments has been built by the Danish company JJ X-RAY in collaboration with DTU.

Together with researchers from DTU, the small Danish company JJ X-Ray has built one of the first two instruments in the European XFEL which enable researchers to see the atoms of a material and how they move.

“We have been involved right from the start; first in the conceptualization stage and later throughout the construction of one of the two instruments, namely the FXE (Femtosecond X-Ray Experiments) instrument. It has been a fantastic assignment which has given us so much exposure that we now receive orders for delivery of components to other major research facilities in the world, including Stanford University in the USA and ESS in Lund,” says CEO of JJ X-Ray, Christian Bjerg Mammen.

In fact, the company has been so successful that it has virtually doubled in size since commencing the assignment for the European XFEL in 2012, increasing its staff from 7 employees at the time to a total of 13 employees. During this process, JJ X-Ray has also received orders to supply parts for the other instruments in the European XFEL, which over time will contain a total of six different instruments.

Even though Denmark only owns a very small part (1 per cent) of the new X-ray laser in Germany, the Danish imprint is large. Both the Chairman of the Management Board and the Chair of the Council are from Denmark, which is not least due to a strong Danish team of researchers with great insight into X-ray lasers and with remarkable results from experiments conducted on other X-ray lasers in the world. 

"One of the trials that we will be conducting is aimed at acquiring greater insight into how we can best harvest solar energy. Using the new X-ray laser, we will be able to see exactly which mechanisms move the charges in a solar cell and transport energy."
Professor Martin Meedom, DTU Physics

Solar cells and light-emitting diodes
In fact, a team of researchers from Denmark will be among the first to have access to conduct experiments in the European XFEL after the inauguration on 1 September. The Danish team of researchers is in charge of two of a total of 14 planned experiments, and the main part of the members of the research team, including the Chair of the European XFEL Council, come from DTU.

“One of the trials that we will be conducting is aimed at acquiring greater insight into how we can best harvest solar energy. Using the new X-ray laser, we will be able to see exactly which mechanisms move the charges in a solar cell and transport energy. At the same time, we can directly see how different environments, such as, for example, water and ethanol, affect the process. This knowledge will enable us to find out which materials are best suited for production of solar cells and photocatalysts because they guarantee the largest harvest of solar energy,” says Professor Martin Meedom, DTU Physics and Chair of the European XFEL Council.

The second trial concerns molecules in organic light-emitting diodes—the light used in mobile phone screens, among other applications.

The X-ray light in the European XFEL is extremely intensive and one billion times stronger than at other X-ray facilities in the world. At the same time, the wavelength of the X-ray light in the new plant is 500 times shorter than ordinary light, making it possible to take X-rays and films of the atoms in a material and see how they move.

Disruptive research
According to Martin Meedom Nielsen, the research opportunities offered by the inauguration of the European XFEL are of such a calibre that they can best be characterized as disruptive research.

“The potential is huge—in addition to solar cells and light-emitting diodes, you can, for example, study protein folding and thus see how, for example, a disease like Alzheimer’s originates. The next step will be to understand how to slow down the development of the disease medically or perhaps even cure it. This opens up fantastic perspectives and offers Denmark a unique opportunity to be right at the forefront of developments. However, this requires that we develop the Danish utilization of the European XFEL,” says Martin Meedom Nielsen.

Martin Meedom Nielsen therefore hopes that even more Danish researchers realize that the new X-ray laser offers an opportunity to gain completely new insights into the properties of materials and that they therefore locate part of their experiments in the European XFEL.

About European XFEL

The European XFEL is the largest and most powerful of the total of 5 X-ray lasers in the world. It is capable of taking X-rays and films at a speed of 27,000 ultrashort light flashes per second. This makes it possible to gain unique insight into the inner structure and dynamics of materials by directly mapping the movements of atoms and how electrical charges and spins interact with each other in both technological and biological materials.

The plant is 3.4 km long with an accelerator tunnel of 2.1 km, in which bunches of electrons are accelerated up to a hair’s breadth below the speed of light and are thereby prepared for generation of X-ray laser light. This takes place in a 200-m long section in which more than 17,000 magnets force them out into a ‘slalom course’, where they give off X-ray laser light at each turn.

When it has been fully extended, the European XFEL will contain more instruments that can work with the X-ray laser light concurrently. One of the instruments is developed and built jointly by DTU and the Danish company JJ X-Ray.