World’s Biggest X-Ray Laser Beams Its First Light: Why It Matters
The European XFEL, the crème de la crème of X-ray radiation lasers currently existent in the world, is up and running and has successfully completed its first lasing.
Scientists at the German research center DESY, in Hamburg, fired the European XFEL on Thursday, May 4, to witness its first X-ray beam, thus reaching "the last major milestone" before the facility is officially opened in September.
"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 colors," said Professor Robert Feidenhans'l, European XFEL managing director.
Come autumn, international research teams will be able to harness the power and accuracy of the X-ray laser for the benefit of scientific experiments, paving the way for "a new era of research in Europe" and throughout the world.
By then, DESY and European XFEL representatives estimate two scientific instruments will be fully operational and ready to welcome external users. This number will eventually be extended to six.
The Biggest X-Ray Laser In The World
There are only five X-ray lasers worldwide, and the European XFEL is the largest and most powerful laser of them all. The laser is housed in an underground facility that stretches for 3.4 kilometers (or about 2.1 miles).
The European XFEL is an X-ray laser of superlatives. It generates synchrotron radiation in X-ray range, emitting electrons that are accelerated to relativistic speed (close to speed of light). Its X-ray laser is extremely intense and a billion times brighter than conventional synchrotron light sources.
The laser light is produced with what DESY describes as "the most advanced and most powerful linear accelerator in the world."
The first lasing of the European XFEL yielded an X-ray beam of 0.8 nanometers in wavelength, about 500 times shorter than the wavelength of visible light.
During the test, the X-ray laser recorded a repetition rate of one pulse per second. Once the European XFE is running at full capacity, the laser will generate 27,000 pulses per second, each so short and intense that researchers can make pictures of structures and processes at the atomic level. By comparison, the previous was of just 120 pulses per second.
How The European XFEL Works
The laser fires streams of electrons that go through an accelerator tunnel 2.1 kilometers (or about 1.3 miles) in length. Here, the electron pulses are accelerated and travel at near-light speed and very high energies through a photon tunnel.
This tunnel contains a stretch of X-ray generating devices 210 meters long (or about 689 feet), where a series of more than 17,000 permanent magnets drive the beams through a lengthy series of mirrored tunnels.
The magnets have alternating poles and are called undulators. They interact with the electron pulses from above and below, steering the electrons into a "slalom" course.
At each turn, the beams release extremely short-wavelength X-ray radiation which magnify over the course of each beam's trip through the tunnels.
"We can now begin to direct the X-ray flashes with special mirrors through the last tunnel section into the experiment hall, and then step by step start the commissioning of the experiment stations," explained Feidenhans'l.
Cool Scientific Applications For The European XFEL
Once in operation, the key component of the XFEL — the superconducting linear accelerator — will generate the fastest, most powerful laser pulses on the planet. The laser facility will also be extremely versatile, capable of conducting biological, chemical and physical experiments.
According to a DESY and European XFEL joint news release, the wavelength of the X-ray laser light corresponds to the size of an atom, which means that "the X-rays can be used to make pictures and films of the nanocosmos at atomic resolution."
"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," noted Helmut Dosch, DESY chairman.
In other words, the XFEL will allow scientists to better study biomolecules, leading to a more complex understanding of how diseases progress. This will enable researchers to develop novel therapies.
Another scientific application of the European XFEL is a more comprehensive study of chemical processes and their catalysts, in an effort to improve their efficiency and make them less harmful to the environment.
Other areas of interest include materials research and investigating conditions similar to those found in the interior of planets.
The superconducting linear accelerator was developed by DESY, the largest shareholder of the European XFEL, and made operational on April 19.
"The European XFEL's particle accelerator is the first superconducting linear accelerator of this size in the world to go into operation. With the commissioning of this complex machine, DESY and European XFEL scientists have placed the crown on their 20-year engagement in developing and building this large international project. The first experiments are within reach, and I am quite excited about the discoveries ahead of us," said Dosch at the time.