First images of the XFEL-laser inspire researchers

It's barely a year since the European XFEL (X-Ray Free-Electron Laser) was launched, with the first scientists getting their "beam time" on, and already an international team has published its first results.

The researchers, led by Professor Ilme Schlichting at the Max Planck Institute for Medical Research in Heidelberg, used the world's largest X-ray laser to describe three different protein molecules in plants.

They took thousands of pictures of the molecules. This enabled the scientists to calculate three-dimensional models that were then good enough to allow the scientists to tell the molecules apart.

Adrian Manusco, senior scientist at the experimental station at the European XFEL, describes the publication of their results in the journal Nature Communications as a "milestone." 

In a next step, Manusco says he wants to use the system to film the molecules in action for so-called "molecular movies." 

One year ago: The XFEL began operation

It sounds like science fiction - an X-ray camera that is not only detailed enough to capture pictures of individual atoms but that can even document the course of chemical reactions as they are happening.

The facility began operations on September 1st, 2017 in Germany. The plant's incredible, atomic-level abilities requires something quite huge in terms of construction: The giant apparatus capturing tiny molecules measures more than 3.4 kilometers (roughly two miles), going all the way from the German Electron Sychrotron (DESY) in Hamburg to Schenefeld in the state of Schleswig-Holstein.

A huge variety of experiments

In the beginning, the X-ray laser provided light for two laboratories. Over time, the number of these labs will gradually increase. Seven pipes are delivering rays to different labs, with each of those pipes appearing somewhat like a water pipe. Inside is an X-ray laser beam - a special kind of light source that makes it possible to shoot three-dimensional pictures of atoms.

The laboratories offer researchers possibilities that unknown thus far. Materials scientists can investigate the properties of nano materials. Physicists can expose matter to extreme pressures and temperatures and find out how it reacts under high energy density. They can create conditions like those in the early stages of our universe. Or they can use highly precise spectrometry to solve other questions. 

Biochemists and medical researchers can take a close look at biomolecules: What, exactly, do the three-dimensional structures of cells look like? They can also use the imaging to decipher the molecular structure of viruses.

Extremely short, extremely bright

The X-ray flashes coming out of the machine take only about 0.00000000000001 seconds, or ten femtoseconds. There are 27,000 such flashes every second. Their wavelength is extremely short: 0.005 to 4.7 nanometers. That's enough to provide images of atoms in detail.

The incredibly high number of pictures per second in turn makes it possible to take slides of chemical reactions while they are still taking place. Up to this point that had been totally unthinkable: Chemistry, as we know it, is based entirely on the idea that we look at a a substance before and after the chemical reaction. Then, using our understanding of physics and mathematics, we try to understand what probably happened to atoms and molecules in between. Now, chemists can observe this firsthand. They can create movies of chemical reactions.

Furthermore, the X-ray laser is considerably brighter than anything comparable. During its peaks, the XFEL reaches a brilliance of about one billion times higher than that of any other common X-ray. Even at its average setting it is still about ten thousand times more powerful.

Several kilometers of tunnel

The X-ray flashes consist of special pulsed packages of electrons. A pulsed laser produces the electrons by hitting a metal target. Then, the particles travel through an acceleration track 1.7 kilometers long.

The linear accelerator consists of superconducting chambers, inside of which a microwave oscillates and pushes the particles to almost the speed of light. The chambers are cooled down to minus 271 degrees Celsius to enable electrical current in the plant to flow without resistance. All of thise takes place inside a tunnel between 15 and 38 meters underground.

At an energy of up to 17.5 billion electron volts, the electrons first reach a redistribution station, where they are split up into different pipes. That's to make them available to a large number of scientists, who can then use them for experiments in different labs. At the end of the track, they reach the research campus in Schenefeld after 3.4 kilometers.

Built by Europeans for all scientists

Teams of scientists from 35 universities and research institutions from all over the world are currently conducting research at the European XFEL. Scientists were eagerly waiting to start projects at the new facility, which they have been preparing for years. The first two groups of researchers who' ve gotten access to the labs in 2017 also included a team around Australia' s Anton Barty. Another group was led by Polish researcher Wojciech Gawelda. Both work at the DESY. British and Russian scientists have also received early research time. 

XFEL is a Europe-wide research project. Germany covers 58 percent of the costs and Russia 27 percent. Denmark, France, Italy, Poland, Sweden, Switzerland, Slovakia, Spain and Hungary also take part, with each covering between one and three percent of the costs.