On the first stop of his Hamburg visit, German Federal President Horst Köhler came to the German Electron Synchrotron DESY this morning, where he took a tour of the new X-ray laser facility FLASH in the company of his wife, Eva Luise Köhler, and the First Mayor of the City of Hamburg, Ole von Beust. “With his visit, Federal President Köhler acknowledges a worldwide unique pioneering facility that has been available in Hamburg for researchers from various natural sciences for over a year. FLASH not only plays a pioneering role for the superconducting accelerator technology. With regard to the research opportunities at the planned European X-ray laser XFEL, FLASH also lays the foundation for completely new insights into the structure and dynamics of the nanoworld,” said Professor Albrecht Wagner, Chairman of the DESY Board of Directors, who welcomed the Federal President in the FLASH experimental hall together with Professor Jürgen Mlynek, President of the Helmholtz Association, and other members of the DESY Board of Directors.

Federal President Köhler’s main points of interest during his DESY visit were the unique research light sources FLASH and XFEL, whose ultra-short X-ray laser flashes will open up completely new perspectives for various areas of natural science research, but also for industrial companies. The 260-meter-long FLASH facility is located on the DESY site and has been in operation for more than one year, i.e. it could be presented “live” to the Federal President. On his walk through the FLASH tunnel, he took a close look at the ultra-modern superconducting technology used to accelerate the electrons, and at the sophisticated magnet sections in which the brilliant laser flashes are generated.

FLASH is currently the worldwide only free-electron laser facility to produce radiation in the soft X-ray range. It thus plays an important pioneering role for future FEL facilities that will generate laser flashes of even shorter wavelengths. Among these will be the 3.4-kilometer-long European X-ray free-electron laser XFEL, whose realization is currently being prepared at DESY in international cooperation, and which should take up operation in 2013. DESY was able to present Federal President Köhler two recent important XFEL milestones: the approval statement for the construction and operation of the European XFEL facility, and the Technical Design Report, the “key document” containing all the basic information on the technical design and the research potential of the XFEL.


FLASH – The Free-Electron Laser in Hamburg
The FLASH facility took up operation in August 2005 under its former name “VUV-FEL”; it is the worldwide first and currently the only free-electron laser in the soft X-ray range. FLASH plays a ground-breaking role in several respects. The facility generates radiation of the shortest wavelengths ever attained with a research light source of this kind, delivering wavelengths ranging from 50 down to 13,7 nanometers (billionths of a meter). In addition at 2,8 nanometers, a specific part of the radiation, the so-called fifth harmonic even approaches the hard X-ray range of the electromagnetic spectrum. This opens up completely new experimental opportunities for researchers from nearly all the natural sciences, since the shorter the wavelength of the radiation, the smaller the structures that can be studied or created with it – hence the worldwide competition between developers of radiation sources towards ever shorter wavelengths.

“FLASH is not only acting as a driver for the superconducting accelerator technology. It also plays a pioneering role for the European X-ray laser XFEL and other radiation sources of this kind in many other respects: for instance concerning the development of the special magnet arrangements used to generate the X-ray laser flashes, the development of optical components and measuring apparatus, and the electronic processing of large amounts of data,” explained DESY Research Director Professor Jochen R. Schneider. “The participation in FLASH is also very attractive for industrial companies, because they can qualify themselves for the construction of the planned International Linear Collider ILC, the next big challenge of particle physics, through their contribution to FLASH and later to the XFEL.”

FLASH also sets new standards in terms of brilliance: Its peak brilliance surpasses that of the most modern, accelerator-based radiation sources by a factor of ten million and thus enables researchers to carry out investigations that were unfeasible so far, e.g. of astrophysical processes on extremely diluted samples. The extremely short duration of its radiation pulses, which last only 10 to 50 femtoseconds (thousand million millionths of a second), is especially important. Like an ultra-fast stroboscope, it allows scientists to directly observe the formation of chemical bonds or the processes that occur during magnetic data storage.

FLASH has been available for research at currently four experimental stations for more than one year. Around 200 scientists from 60 institutes in 11 countries use the intense laser light for their experiments. Many further projects in various areas of physics, chemistry or molecular biology have already been proposed.


The Superconducting Accelerator Technology
DESY’s free-electron laser also breaks new ground in the technological area: FLASH operates according to the novel SASE principle of “self-amplified spontaneous emission”, which makes use of electrons from a particle accelerator. These fly through a periodic arrangement of magnets, the so-called undulator, that forces them onto a slalom course on which they emit the shortwave, intense flashes of laser light. One special characteristic here is the use of superconducting accelerator technology to bring the electrons up to the requisite high energies. This superconducting technology was developed and tested at DESY from 1992 to 2004 by the international team of the TESLA Collaboration. Inside the accelerator elements, the so-called resonators, which are cooled to a temperature of minus 271 degrees Celsius, the electric current flows with no losses whatsoever. This makes it an extremely efficient and energy-saving method of acceleration, since nearly the entire electric power is transferred to the particles. Moreover, the superconducting resonators deliver a very fine and even electron beam of extremely high quality. Such a special electron beam is the absolute prerequisite for the operation of an X-ray laser.
The superconducting TESLA accelerator technology forms the basis for two other large-scale projects: the European X-ray laser XFEL, whose construction will begin in a few months and whose linear accelerator will be around 1.5 kilometers long, and the future project of particle physics, the International Linear Collider ILC, which is being planned and proposed in a worldwide cooperation. The accelerating sections of the ILC, which will both be up to 20 kilometers long, will also be constructed using superconducting resonators. The operation of the 120-meter-long linear accelerator of FLASH will provide important insights for both projects.

The European XFEL Facility
In February 2003, the German Federal Ministry of Education and Research gave the green light for the X-ray laser, which was proposed by DESY and is to be realized as a European project (X stands for X-ray, FEL for free-electron laser). The X-ray laser will enable leading-edge research in Europe and guarantee a major role for Germany as a location for research and industry.
The XFEL will produce high-intensity ultra-short X-ray flashes with the properties of laser light. This new light source, which can only be described in terms of superlatives, will open up a whole range of new perspectives for the natural sciences. It could also offer very promising opportunities for industrial users. The inconceivably brief and intense X-ray pulses will enable researchers to record what are essentially films with atomic resolution – for example, of how a chemical reaction progresses, how biomolecules move, or how solids are formed. This will benefit a wide range of natural sciences – from physics and chemistry to materials science, geological research and the life sciences. Industrial users will also profit from the facility – for instance from the ability to develop new materials in the nanoworld; i.e., with dimensions measured in billionths of a meter.
Professor Massimo Altarelli, Italian physicists and European XFEL Project Team Leader: “The new XFEL X-ray laser facility will be unique in Europe and offer fascinating perspectives for science. For the first time, it will be possible to analyze the different states of matter on the atomic length and time scale. The future users of the XFEL expect results of fundamental importance in fields such as materials science, plasma physics, structural biology, geological research or chemistry, which could pave the way for new applications, e.g. in biomedicine and pharmacy, or for instance for the optimization of combustion and catalysis technologies.”
The 3.4-kilometer-long XFEL facility will be located in the federal states of Hamburg and Schleswig-Holstein and comprise three large sites. The facility will begin on the DESY site in Hamburg-Bahrenfeld and run in a north-western direction to the town of Schenefeld (Pinneberg district, Schleswig-Holstein), which borders on Hamburg. Here, the research campus with an underground experimental hall comprising ten measuring stations will be realized until 2013. A second experimental complex with another ten measuring stations is foreseen for construction at a later date.
The preparation of the XFEL project recently reached two important milestones: 1) On July 25, 2006, DESY’s XFEL project group and the European XFEL project team published the Technical Design Report for the European XFEL facility. On a total of 580 pages, the 270 authors from 69 institutes in 17 countries describe all the scientific and technical details of the research facility. 2) On August 9, 2006, the authority for mining, energy and geology in Clausthal-Zellerfeld, which is in charge of the XFEL public planning approval procedure, published the approval statement comprising the necessary statutory single permissions for the construction and operation of the XFEL facility. Construction work is thus expected to begin on all three sites in the first half of 2007.
The construction cost for the XFEL facility amount to 986 million Euro. As the host country, Germany will cover up to 60 percent of these costs, at least 40 percent will be born by European partner countries. Until now, 11 European countries and the People’s Republic of China declared their intention to participate in the XFEL. Concrete bilateral negotiations are currently taking place on the governmental level between Germany and the various interested countries to determine the nature and scale of each country’s participation. The goal is the foundation of an independent European XFEL research organization by mid-2007.

The German Electron Synchrotron DESY, Member of the Helmholtz Association
The research center DESY (“Deutsches Elektronen-Synchrotron”) is one of the world’s leading accelerator centers for exploring the structure of matter. Its research spectrum covers three areas: accelerator development, research with photons and particle physics. Research with photons is carried out at the Hamburg Synchrotron Radiation Laboratory HASYLAB at DESY. Physicists, chemists, geologists, biologists, physicians and materials scientists use the intense radiation generated in the accelerators DORIS and PETRA to investigate various samples in atomic detail. The free-electron laser FLASH has been available as a further light source since 2005. From July 2007 on, 225 million Euro will be employed to convert the accelerator PETRA into the world’s best storage ring-based source of energetic X-ray radiation providing a total of 30 experimental stations. “PETRA III” will take up operation in 2009. In conjunction with the European X-ray laser XFEL, these new light sources will guarantee DESY’s leading position in the field of research with photons.
Particle physics at DESY is carried out at the 6.3-kilometer-long Hadron-Electron Ring Accelerator facility HERA. Using this “super electron microscope”, physicists can investigate the inner structure of the proton and the fundamental forces of nature. DESY also takes part in the next big challenge of particle physics: the International Linear Collider ILC, an accelerator delivering electron-positron collisions at the highest energies. The ILC will allow physicists to gain a deeper insight into the structure and origin of matter and the universe than was ever possible before.
DESY is a member of the Helmholtz Association of German Research Centers, and a publicly funded national research center with two locations, in Hamburg and in Zeuthen (Brandenburg). Research at the particle accelerators is carried out in international cooperation. 2750 scientists from 33 countries come to DESY every year; 950 of them are working at the HERA accelerator in the field of particle physics, a further 1800 guests use the Hamburg Synchrotron Radiation Laboratory HASYLAB. DESY has 1600 employees, 200 of which are working in Zeuthen. DESY’s yearly budget amounts to 160 million Euro (145 million Euro for the Hamburg site and 15 million Euro for the Zeuthen site).