Full concentration

© Graphic | ELI Beamline, Gernot Walter

Close to Prague, a unique laser center is being developed to open up completely new research possibilities for physicists, medical scientists and materials scientists.

A light source that is two hundred times more powerful than all the power plants on earth combined, and flashing so fast that its beam only has time to travel as far as a hair’s thickness — that’s impossible, isn’t it? Not at ELI Beamline. Close to Prague, a research center is being built that will house the world’s most powerful lasers. It is one of four ELI (Extreme Light Infrastructure) laser centers with which the European Union intends to take the lead in laser research. Lasers have seen rapid development in the past few years. Now there are ultra-short pulse lasers and lasers with ever more power.

There is more

More About ELI Beamline:

The project Extreme Light Infrastructure (ELI) is part of a European plan to build a new generation of large research facilities selected by the European Strategy Forum for Research Infrastructures (ESFRI). ELI will be operated according to a new model designed for a consortium of European research infrastructures (ERIC).

ELI equals three laser centers combined under one heading:

  • ELI Beamlines will be located in the Czech Republic and will create a new generation of secondary sources for interdisciplinary applications in physics, medicine, biology and material sciences.
  • ELI Attosecond is being arranged in Hungary and is to be focused on physics of ultrashort optical pulses in attosecond order.
  • ELI Nuclear Physics aimed at photonuclear physics should be located in Romania.

Detailed Research Activity Description:

ELI_Beamlines_logo_laser

The objective of this Research Activity is to deliver the laser system, the principal instrument and the backbone of the whole ELI facility. More

About the Author:

Dr. Georg Korn is from Berlin, where he worked for many years as a researcher at the Max Born Institute. After working for a company that produces eye lasers, he moved to work in the USA, first at the University of Michigan’s laser center and then at the University of California, San Diego. Currently, he is the scientific coordinator for research programs and chief scientist at ELI Beamline in Prague.

 

Full-service laser center

There have also been promising efforts to use lasers to accelerate particles and produce X-rays. But what doesn’t exist yet is a one-stop shop where researchers have all of these properties available to them as tools, so they can concentrate on their research questions — a full-service laser center, so to speak. That’s the idea behind ELI. Three such centers will be built in Szeged (Hungary), Măgurele (Romania) and Prague (Czech Republic), each with a different research focus. A fourth center is planned but its location is not yet fixed. 85 percent of the financing for the construction of the ELI centers, all in new EU member states, is from European Union infrastructure funds.

ELI Beamline will do all sorts of things — including producing anti-matter and rearranging molecules in fractions of a second.

Operating costs will be met by the European Research Infrastructure Consortium. I’m responsible for ELI Beamline as scientific coordinator for research programs. Close to Prague, the Czech capital, we’re currently building the first high-power facility available to researchers from science and industry. It will offer the most powerful lasers and a full-fledged research infrastructure, all under one roof. The building should be finished by 2015. Then we’ll install the first lasers and regular research work should be underway by 2018.

Which beam would you like?

ELI Beamline will feature four lasers with various properties. The most powerful of these will deliver a record-breaking 10 petawatts of power; a petawatt is one quadrillion watts. For comparison, all the world’s power plants add up to only 50 terawatts — or just two hundredths the power of our laser. We can achieve this because the power is compressed into an extremely short period of time — approximately 20 femtoseconds; a femtosecond is one quadrillionth of a second. Here’s another startling comparison: If you turn on a flashlight for one second, light will travel from the Earth to the Moon in that time. When we turn on our laser, the pulse is only long enough for light to travel a mere six micrometers — meaning it covers less than a hair’s width.

The most powerful laser of ELI Beamline will deliver a record-breaking 10 petawatts of power; a petawatt is one quadrillion watts.

As our master laser we’re using a very stable, Ti:sapphire laser that is powered by a diode-pumped solid-state laser and produces light at a wavelength of 830 nanometers, which is near infrared. With a pulse repetition frequency of 80 MHz, it emits exact light pulses that we can separate with a combination of cleverly constructed gratings and mirrors. That way, various wavelengths of light arrive at different times. We can amplify specific sections of the light spectrum using cascaded or neodymium-doped glasses. Otherwise it wouldn’t be possible to build up this tremendous power.

ELI Bemline breaks records

After passing through the amplifiers, the spectrum is compressed again into the ultra-short pulse, which now has a hundred thousand times higher peak power. The resulting light beam, 20 centimeters wide, is narrowed to a few micrometers. In this way, we hope to get up into the range of 1,024 watts per square centimeter. That, too, will set a world record.Such records are impressive, but they are not what ELI Beamline is setting out to achieve.

Combining two or three different beam types opens up completely new research options.

The lasers are really intended to give researchers an even more detailed look into new materials or biological samples. And they will open up entirely new perspectives for research — such as finding out about special effects in quantum electrodynamics. For instance, physicists hypothesize that photons, the energy quanta of light, are converted into mat-ter — an electron and a positron — at high energy densities and intensities. And all that happens in a vacuum, out of nothing. Whether we’ll actually see this phenomenon at ELI Beamline is not clear, but the chances are better there than they are anywhere else.

Cleverly combined

Another interesting option that isn’t available in quite the same way anywhere else is the way in which various beam types can be combined. In addition to laser light, ELI Beamline will produce high-energy electrons and protons. The electrons are accelerated by having them “sur f” on a wave of light until they approach the speed of light.

We produce electrons at energies of well over a gigaelectronvolts; our protons have more than 100 megaelectronvolts. This brings us into the energy range of large accelerators several kilometers long. Yet we need only a few centimeters for our lasers to give the particles the same amount of energy. Along with the Helmholtz Desy Center in Hamburg, we’re developing the Laser Undulator X-Ray (LUX). LUX is a compact electron particle accelerator that prepares the electron package so that it can be used directly in an undulator for generating X-rays in a water window.

The light of each laser can be fed through a distribution system to each laboratory.

In addition to laser light and particles (electrons and protons), ELI Beamline will give researchers the opportunity to experiment with X-rays. Combining two or three different beam types opens up completely new research options. For instance, it’s conceivable that proteins could be excited with electrons or photons and simultane-ously examined using X-rays to observe how the complicated molecules rearrange themselves in fractions of a second. You could even record the folding process of proteins subjected to different stimuli much in the same way as in a movie.

High quality standards

Although ELI Beamline is a research entity, it benefits from industry participation. At the same time, it drives industrial development in that the companies involved can use it to test and improve their products at the cutting edge of research. Many of the high-repetition picosecond pump lasers delivering output light for the amplifier segments are provided by TRUMPF Scientific Lasers. What’s important to us is the experience gained from applications in automotive manufacturing, for example, because it’s an industry that demands the highest levels of quality and reliability. ELI Beamline sees itself as a service institution that thrives on user satisfaction. Only if our customers achieve their research goals on schedule will they receive further funding from their national research organizations, which also fund the operating costs at ELI Beamline.

Required fields: Comment, Name & Mail (Mail will not be published).