Speaking at the launch ceremony in Hamburg today, the German federal minister of education and research Annette Schavan said: "The funding negotiations with the 12 interested countries are so far advanced that the construction of this new research facility, which is very much sought after by the scientific community, can now begin."

Normal lasers can generate extremely intense, ultrashort pulses of light, but the wavelength of the radiation is too long to pinpoint the location of atoms. A free-electron laser can generate radiation at shorter wavelengths by accelerating bunches of electrons and passing them through a periodic magnet called an undulator. This forces the electrons to continually change direction and so emit synchrotron radiation in the "hard" X-ray portion of the electromagnetic spectrum.

XFEL, which has strong connections to the DESY research centre in Hamburg, is an international project that is three-quarters funded by Germany with the remaining money from other European countries and China. It will accelerate electron bunches using 3.4 km of superconducting magnets to energies of 20 GeV, generating laser pulses billions of times brighter than the beams in today's synchrotron devices. In theory, these pulses will be able to reveal the atomic structures of membrane patterns and generate atomic- and femotosecond-resolution images of plasmas.

XFEL will follow two other X-ray free-electron-laser projects around the world. These are the LCLS in the US, due to start up in 2009, and the Japanese SCSS facility, which is scheduled to come online in 2011. DESY is already home to FLASH, which is a prototype free-electron laser that operates at longer "soft" X-ray wavelengths.

In a communiqué signed during the launch ceremony in Hamburg, the representatives of the partner countries declared: "We are convinced that it is appropriate to begin the construction of the XFEL as quickly as possible in view of the international competition."