PHOTON SCIENCE

FLASH, the Free-Electron LASer in Hamburg, is the first free-electron laser worldwide to produce femtosecond pulses of soft X-rays in 2005. The European XFEL facility, which is currently under construction, will deliver hard X-ray pulses far shorter than those from any other X-ray source, and their peak brilliance will be six to eight orders of magnitude higher. The unprecedented shortness and intensity of the X-ray pulses as well as their coherence open entirely new fields of research.


The Free-Electron Laser (FEL) principle has been known since the early 1970s, but it became clear only in recent years that these devices have the potential of becoming exceedingly powerful light sources in the X-ray regime.