VUV free-electron laser starts at DESY

The first user operation of the VUV free-electron laser (FEL) at DESY, Hamburg in Germany is now under way. German Chancellor Gerhard Schroeder paid a visit to the facility to join the celebrations. The VUV-FEL employs the new technology developed at DESY from 1992 to 2004 by the international team as part of the TESLA Collaboration. Electrons are brought to high energies by a superconducting linear accelerator, and then race through an undulator, which is a periodic arrangement of magnets that forces the electrons to follow a slalom course and thereby radiate flashes of light. According to self-amplified spontaneous emission (SASE), the process finally generates intense flashes of short-wavelength laser light. Its peak brilliance surpasses that of the most modern synchrotron radiation sources by a factor of ten million. Its radiation is coherent, and its wavelength is tunable within a range of 6 to 30 nm. The very intense radiation pulses have an extremely short duration of 10~50 femto seconds. Five experimental stations have been constructed at the facility. For more information, visit the Web page, http://www.desy.de