Operation of FLASH at 6.5 nm Wavelength

FLASH, the Free-Electron Laser at DESY, Germany has been upgraded in 2007. A sixth accelerating module with eight 9-cell superconducting cavities of the TESLA type has been installed. In addition, another module has been replaced and tuners of a third module have been repaired. In September 2007, a beam energy of 1 GeV has been achieved for the first time, followed by lasing at 6.5 nm shortly after. With this remarkable achievement, the initial design goals of the FEL in terms of beam energy and wavelength have been reached.