European XFEL generates its first laser beam

European XFEL generates its first laser light

The world’s biggest X-ray laser called European XFEL has reached the last major milestone, its first X-ray laser light, ahead of its official opening in September this year.

Most of the 3.4-kilometer-long facility is located in underground tunnels. It produced its first X-ray laser light with a wavelength of 0.8 nm – roughly five hundred times shorter than that of perceptible light.

At the very first lasing, the European XFEL produced laser with a repetition rate of one pulse per second that will later boost to a whopping 27 000 per second.

Prof. Robert Feidenhans'l, the managing director of the European XFEL, said, “The European XFEL has generated its first X-ray laser light. The facility, to which many countries around the world contributed know-how and components, has passed its first big test with flying colours.”

Feidenhans'l added that the researchers could now start to direct the X-ray flashes using special mirrors through the last section of the tunnel into the experiment hall, and then gradually begin the experiment stations’ commissioning.

At the start of September 2017, the European XFEL, which is the most powerful of the five X-ray lasers worldwide, will be officially opened. External users will be able to conduct experiments at the initial two of the eventual half a dozen scientific instruments.

Electrons are accelerated to an energy of up to 17.5 GeV by a 2.1 km long linear accelerator with superconducting RF-cavities. The use of superconducting acceleration elements developed at DESY allows up to 27,000 repetitions per second, significantly more than other x-ray lasers in the US and Japan can achieve. The electrons are then introduced into the magnetic fields of special arrays of magnets called undulators, where they follow curved trajectories resulting in the emission of x-rays in the range of 0.05 to 4.7 nanometres.

Helmut Dosch, Chairman of the DESY Directorate, said: "The European X-ray laser has been brought to life! The first laser light produced today with the most advanced and most powerful linear accelerator in the world marks the beginning a new era of research in Europe. This worldwide unique high-tech facility was built in record time and within budget. This is an amazing success of science. I congratulate all those involved in the research, development, and construction of this facility with passion and commitment: the employees of DESY, European XFEL, and international partners. They have achieved outstanding results and demonstrated impressively what is possible in international cooperation. The European XFEL will provide us with the most detailed images of the molecular structure of new materials and drugs and novel live recordings of biochemical reactions."
With more than 27 000 light flashes per second instead of the previous maximum of 120 per second, an extremely high luminosity, and the parallel operation of several experiment stations, it will be possible for scientists investigate more limited samples and perform their experiments more quickly. Therefore, the facility will increase the amount of beamtime available, as the capacity at other X-ray lasers worldwide has been eclipsed by demand, and facilities have been overall overbooked.