DESY, Hamburg
The free-electron laser user facility FLASH at DESY, Germany is world-wide the only SASE-FEL operating in the VUV and the soft X-ray wavelengths range. Since summer 2005, FLASH operates as a user facility providing almost fully coherent, 10 femtosecond long laser radiation in the wavelength range from 47 nm to 6.5 nm with an unprecedented brilliance - many orders of magnitude higher than conventional facilities. The SASE radiation contains also higher harmonics. Several experiments have successfully used the third and fifth harmonics, in the latter case down to a wavelength of 1.59 nm. Starting autumn 2009, FLASH will be upgraded with an additional superconducting TESLA type accelerating module boosting its beam energy to 1.2 GeV. This will allow lasing below 5 nm. In addition, a 3rd harmonic accelerating module will be installed, which improves the longitudinal phase space and the overall performance of the facility.
DESY, Hamburg
At the European XFEL circular polarized radiation in the wavelength range 0.4-1.6 nm is highly desired. An economically and technically convenient method is to utilize a long planar undulator to pre-bunch electron beam first and then pass it through a shorter and specially designed undulator to generate arbitrary polarized radiation. Between these two parts, the electrons and the radiation from the long undulator must be spatially separated by a bend. In this paper, a solution for an isochronous bend is presented considering nonlinear aberrations, which preserves theμbunching even for the 0.4 nm case.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
DESY, Hamburg
BESSY GmbH, Berlin
Imperfections on the surfaces of the optical components of photon transport systems can degrade the quality of the radiation, causing amongst other effects structure in the transverse beam profile. This effect is being investigated for one of the beamlines at FLASH. The FEL mirror surfaces have been measured in the metrology laboratory at Helmholtz Zentrum Berlin / BESSY-II, and these data are input into wavefront propagation calculations, which model the transport of the radiation field from the exit of the FEL across the optics to the experiment. The input fields for the propagation were generated using the Genesis1.3 code. This work is part of collaboration in the IRUVX-PP consortium.