FLASH UPGRADE

The free-electron laser FLASH at DESY is the worldwide leading FEL user facility operating in the VUV and the soft X-ray wavelength range. Since summer 2005, FLASH has provided coherent femtosecond laser radiation for user experiments with photon wavelengths from 47 nm to 6.8 nm in the fundamental. Autumn 2009, FLASH will be upgraded with an additional superconducting TESLA type accelerating module boosting the electron beam energy up to 1.2 GeV. This will allow lasing with wavelengths below 5 nm. In addition, a module with four third harmonic superconducting cavities will be installed to linearize the longitudinal phase space and thus to improve the overall performance of the facility.